Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 3926 insertions, 0 deletions

diff --git a/Source/WebCore/rendering/RenderBox.cpp b/Source/WebCore/rendering/RenderBox.cpp
new file mode 100644
index 000000000..40adf387e
--- /dev/null
+++ b/Source/WebCore/rendering/RenderBox.cpp
@@ -0,0 +1,3926 @@
+/*
+ * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
+ *           (C) 1999 Antti Koivisto (koivisto@kde.org)
+ *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
+ *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
+ * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "config.h"
+#include "RenderBox.h"
+
+#include "CachedImage.h"
+#include "Chrome.h"
+#include "ChromeClient.h"
+#include "Document.h"
+#include "FrameView.h"
+#include "GraphicsContext.h"
+#include "HitTestResult.h"
+#include "htmlediting.h"
+#include "HTMLElement.h"
+#include "HTMLNames.h"
+#include "ImageBuffer.h"
+#include "FloatQuad.h"
+#include "Frame.h"
+#include "Page.h"
+#include "PaintInfo.h"
+#include "RenderArena.h"
+#include "RenderBoxRegionInfo.h"
+#include "RenderFlowThread.h"
+#include "RenderInline.h"
+#include "RenderLayer.h"
+#include "RenderPart.h"
+#include "RenderRegion.h"
+#include "RenderTableCell.h"
+#include "RenderTheme.h"
+#include "RenderView.h"
+#include "ScrollbarTheme.h"
+#include "TransformState.h"
+#include <algorithm>
+#include <math.h>
+
+using namespace std;
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+// Used by flexible boxes when flexing this element and by table cells.
+typedef WTF::HashMap<const RenderBox*, LayoutUnit> OverrideSizeMap;
+static OverrideSizeMap* gOverrideHeightMap = 0;
+static OverrideSizeMap* gOverrideWidthMap = 0;
+
+bool RenderBox::s_hadOverflowClip = false;
+
+RenderBox::RenderBox(Node* node)
+    : RenderBoxModelObject(node)
+    , m_marginLeft(0)
+    , m_marginRight(0)
+    , m_marginTop(0)
+    , m_marginBottom(0)
+    , m_minPreferredLogicalWidth(-1)
+    , m_maxPreferredLogicalWidth(-1)
+    , m_inlineBoxWrapper(0)
+{
+    setIsBox();
+}
+
+RenderBox::~RenderBox()
+{
+}
+
+LayoutUnit RenderBox::marginBefore() const
+{
+    switch (style()->writingMode()) {
+    case TopToBottomWritingMode:
+        return m_marginTop;
+    case BottomToTopWritingMode:
+        return m_marginBottom;
+    case LeftToRightWritingMode:
+        return m_marginLeft;
+    case RightToLeftWritingMode:
+        return m_marginRight;
+    }
+    ASSERT_NOT_REACHED();
+    return m_marginTop;
+}
+
+LayoutUnit RenderBox::marginAfter() const
+{
+    switch (style()->writingMode()) {
+    case TopToBottomWritingMode:
+        return m_marginBottom;
+    case BottomToTopWritingMode:
+        return m_marginTop;
+    case LeftToRightWritingMode:
+        return m_marginRight;
+    case RightToLeftWritingMode:
+        return m_marginLeft;
+    }
+    ASSERT_NOT_REACHED();
+    return m_marginBottom;
+}
+
+LayoutUnit RenderBox::marginStart() const
+{
+    if (isHorizontalWritingMode())
+        return style()->isLeftToRightDirection() ? m_marginLeft : m_marginRight;
+    return style()->isLeftToRightDirection() ? m_marginTop : m_marginBottom;
+}
+
+LayoutUnit RenderBox::marginEnd() const
+{
+    if (isHorizontalWritingMode())
+        return style()->isLeftToRightDirection() ? m_marginRight : m_marginLeft;
+    return style()->isLeftToRightDirection() ? m_marginBottom : m_marginTop;
+}
+
+void RenderBox::setMarginStart(LayoutUnit margin)
+{
+    if (isHorizontalWritingMode()) {
+        if (style()->isLeftToRightDirection())
+            m_marginLeft = margin;
+        else
+            m_marginRight = margin;
+    } else {
+        if (style()->isLeftToRightDirection())
+            m_marginTop = margin;
+        else
+            m_marginBottom = margin;
+    }
+}
+
+void RenderBox::setMarginEnd(LayoutUnit margin)
+{
+    if (isHorizontalWritingMode()) {
+        if (style()->isLeftToRightDirection())
+            m_marginRight = margin;
+        else
+            m_marginLeft = margin;
+    } else {
+        if (style()->isLeftToRightDirection())
+            m_marginBottom = margin;
+        else
+            m_marginTop = margin;
+    }
+}
+
+void RenderBox::setMarginBefore(LayoutUnit margin)
+{
+    switch (style()->writingMode()) {
+    case TopToBottomWritingMode:
+        m_marginTop = margin;
+        break;
+    case BottomToTopWritingMode:
+        m_marginBottom = margin;
+        break;
+    case LeftToRightWritingMode:
+        m_marginLeft = margin;
+        break;
+    case RightToLeftWritingMode:
+        m_marginRight = margin;
+        break;
+    }
+}
+
+void RenderBox::setMarginAfter(LayoutUnit margin)
+{
+    switch (style()->writingMode()) {
+    case TopToBottomWritingMode:
+        m_marginBottom = margin;
+        break;
+    case BottomToTopWritingMode:
+        m_marginTop = margin;
+        break;
+    case LeftToRightWritingMode:
+        m_marginRight = margin;
+        break;
+    case RightToLeftWritingMode:
+        m_marginLeft = margin;
+        break;
+    }
+}
+
+LayoutRect RenderBox::borderBoxRectInRegion(RenderRegion* region, LayoutUnit offsetFromTopOfFirstPage, RenderBoxRegionInfoFlags cacheFlag) const
+{
+    if (!region)
+        return borderBoxRect();
+    
+    // Compute the logical width and placement in this region.
+    RenderBoxRegionInfo* boxInfo = renderBoxRegionInfo(region, offsetFromTopOfFirstPage, cacheFlag);
+    if (!boxInfo)
+        return borderBoxRect();
+
+    // We have cached insets.
+    LayoutUnit logicalWidth = boxInfo->logicalWidth();
+    LayoutUnit logicalLeft = boxInfo->logicalLeft();
+        
+    // Now apply the parent inset since it is cumulative whenever anything in the containing block chain shifts.
+    // FIXME: Doesn't work right with perpendicular writing modes.
+    const RenderBlock* currentBox = containingBlock();
+    offsetFromTopOfFirstPage -= logicalTop();
+    RenderBoxRegionInfo* currentBoxInfo = currentBox->renderBoxRegionInfo(region, offsetFromTopOfFirstPage);
+    while (currentBoxInfo && currentBoxInfo->isShifted()) {
+        if (currentBox->style()->direction() == LTR)
+            logicalLeft += currentBoxInfo->logicalLeft();
+        else
+            logicalLeft -= (currentBox->logicalWidth() - currentBoxInfo->logicalWidth()) - currentBoxInfo->logicalLeft();
+        offsetFromTopOfFirstPage -= logicalTop();
+        currentBox = currentBox->containingBlock();
+        region = currentBox->clampToStartAndEndRegions(region);
+        currentBoxInfo = currentBox->renderBoxRegionInfo(region, offsetFromTopOfFirstPage);
+    }
+    
+    if (cacheFlag == DoNotCacheRenderBoxRegionInfo)
+        delete boxInfo;
+
+    if (isHorizontalWritingMode())
+        return LayoutRect(logicalLeft, 0, logicalWidth, height());
+    return LayoutRect(0, logicalLeft, width(), logicalWidth);
+}
+
+void RenderBox::clearRenderBoxRegionInfo()
+{
+    if (!inRenderFlowThread() || isRenderFlowThread())
+        return;
+
+    RenderFlowThread* flowThread = enclosingRenderFlowThread();
+    flowThread->removeRenderBoxRegionInfo(this);
+}
+
+void RenderBox::willBeDestroyed()
+{
+    clearOverrideSize();
+
+    if (style() && (style()->logicalHeight().isPercent() || style()->logicalMinHeight().isPercent() || style()->logicalMaxHeight().isPercent()))
+        RenderBlock::removePercentHeightDescendant(this);
+
+    // If this renderer is owning renderer for the frameview's custom scrollbars,
+    // we need to clear it from the scrollbar. See webkit bug 64737.
+    if (style() && style()->hasPseudoStyle(SCROLLBAR) && frame() && frame()->view())
+        frame()->view()->clearOwningRendererForCustomScrollbars(this);
+
+    // If the following assertion fails, logicalHeight()/logicalMinHeight()/
+    // logicalMaxHeight() values are changed from a percent value to a non-percent
+    // value during laying out. It causes a use-after-free bug.
+    ASSERT(!RenderBlock::hasPercentHeightDescendant(this));
+
+    RenderBoxModelObject::willBeDestroyed();
+}
+
+void RenderBox::removeFloatingOrPositionedChildFromBlockLists()
+{
+    ASSERT(isFloatingOrPositioned());
+
+    if (documentBeingDestroyed())
+        return;
+
+    if (isFloating()) {
+        RenderBlock* parentBlock = 0;
+        for (RenderObject* curr = parent(); curr && !curr->isRenderView(); curr = curr->parent()) {
+            if (curr->isRenderBlock()) {
+                RenderBlock* currBlock = toRenderBlock(curr);
+                if (!parentBlock || currBlock->containsFloat(this))
+                    parentBlock = currBlock;
+            }
+        }
+
+        if (parentBlock) {
+            RenderObject* parent = parentBlock->parent();
+            if (parent && parent->isDeprecatedFlexibleBox())
+                parentBlock = toRenderBlock(parent);
+
+            parentBlock->markAllDescendantsWithFloatsForLayout(this, false);
+        }
+    }
+
+    if (isPositioned()) {
+        for (RenderObject* curr = parent(); curr; curr = curr->parent()) {
+            if (curr->isRenderBlock())
+                toRenderBlock(curr)->removePositionedObject(this);
+        }
+    }
+}
+
+void RenderBox::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
+{
+    s_hadOverflowClip = hasOverflowClip();
+
+    if (style()) {
+        // The background of the root element or the body element could propagate up to
+        // the canvas.  Just dirty the entire canvas when our style changes substantially.
+        if (diff >= StyleDifferenceRepaint && node() &&
+                (node()->hasTagName(htmlTag) || node()->hasTagName(bodyTag)))
+            view()->repaint();
+        
+        // When a layout hint happens and an object's position style changes, we have to do a layout
+        // to dirty the render tree using the old position value now.
+        if (diff == StyleDifferenceLayout && parent() && style()->position() != newStyle->position()) {
+            markContainingBlocksForLayout();
+            if (style()->position() == StaticPosition)
+                repaint();
+            else if (newStyle->position() == AbsolutePosition || newStyle->position() == FixedPosition)
+                parent()->setChildNeedsLayout(true);
+            if (isFloating() && !isPositioned() && (newStyle->position() == AbsolutePosition || newStyle->position() == FixedPosition))
+                removeFloatingOrPositionedChildFromBlockLists();
+        }
+    } else if (newStyle && isBody())
+        view()->repaint();
+
+    if (FrameView *frameView = view()->frameView()) {
+        bool newStyleIsFixed = newStyle && newStyle->position() == FixedPosition;
+        bool oldStyleIsFixed = style() && style()->position() == FixedPosition;
+        if (newStyleIsFixed != oldStyleIsFixed) {
+            if (newStyleIsFixed)
+                frameView->addFixedObject();
+            else
+                frameView->removeFixedObject();
+        }
+    }
+
+    RenderBoxModelObject::styleWillChange(diff, newStyle);
+}
+
+void RenderBox::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
+{
+    RenderBoxModelObject::styleDidChange(diff, oldStyle);
+
+    if (needsLayout() && oldStyle) {
+        if (oldStyle && (oldStyle->logicalHeight().isPercent() || oldStyle->logicalMinHeight().isPercent() || oldStyle->logicalMaxHeight().isPercent()))
+            RenderBlock::removePercentHeightDescendant(this);
+
+        // Normally we can do optimized positioning layout for absolute/fixed positioned objects. There is one special case, however, which is
+        // when the positioned object's margin-before is changed. In this case the parent has to get a layout in order to run margin collapsing
+        // to determine the new static position.
+        if (isPositioned() && style()->hasStaticBlockPosition(isHorizontalWritingMode()) && oldStyle->marginBefore() != style()->marginBefore()
+            && parent() && !parent()->normalChildNeedsLayout())
+            parent()->setChildNeedsLayout(true);
+    }
+
+    // If our zoom factor changes and we have a defined scrollLeft/Top, we need to adjust that value into the
+    // new zoomed coordinate space.
+    if (hasOverflowClip() && oldStyle && style() && oldStyle->effectiveZoom() != style()->effectiveZoom()) {
+        if (int left = layer()->scrollXOffset()) {
+            left = (left / oldStyle->effectiveZoom()) * style()->effectiveZoom();
+            layer()->scrollToXOffset(left);
+        }
+        if (int top = layer()->scrollYOffset()) {
+            top = (top / oldStyle->effectiveZoom()) * style()->effectiveZoom();
+            layer()->scrollToYOffset(top);
+        }
+    }
+
+    bool isBodyRenderer = isBody();
+    bool isRootRenderer = isRoot();
+
+    // Set the text color if we're the body.
+    if (isBodyRenderer)
+        document()->setTextColor(style()->visitedDependentColor(CSSPropertyColor));
+
+    if (isRootRenderer || isBodyRenderer) {
+        // Propagate the new writing mode and direction up to the RenderView.
+        RenderView* viewRenderer = view();
+        RenderStyle* viewStyle = viewRenderer->style();
+        if (viewStyle->direction() != style()->direction() && (isRootRenderer || !document()->directionSetOnDocumentElement())) {
+            viewStyle->setDirection(style()->direction());
+            if (isBodyRenderer)
+                document()->documentElement()->renderer()->style()->setDirection(style()->direction());
+            setNeedsLayoutAndPrefWidthsRecalc();
+        }
+
+        if (viewStyle->writingMode() != style()->writingMode() && (isRootRenderer || !document()->writingModeSetOnDocumentElement())) {
+            viewStyle->setWritingMode(style()->writingMode());
+            viewRenderer->setHorizontalWritingMode(style()->isHorizontalWritingMode());
+            if (isBodyRenderer) {
+                document()->documentElement()->renderer()->style()->setWritingMode(style()->writingMode());
+                document()->documentElement()->renderer()->setHorizontalWritingMode(style()->isHorizontalWritingMode());
+            }
+            setNeedsLayoutAndPrefWidthsRecalc();
+        }
+
+        frame()->view()->recalculateScrollbarOverlayStyle();
+    }
+}
+
+void RenderBox::updateBoxModelInfoFromStyle()
+{
+    RenderBoxModelObject::updateBoxModelInfoFromStyle();
+
+    bool isRootObject = isRoot();
+    bool isViewObject = isRenderView();
+
+    // The root and the RenderView always paint their backgrounds/borders.
+    if (isRootObject || isViewObject)
+        setHasBoxDecorations(true);
+
+    setPositioned(style()->position() == AbsolutePosition || style()->position() == FixedPosition);
+    setFloating(style()->isFloating() && (!isPositioned() || style()->floating() == PositionedFloat));
+
+    // We also handle <body> and <html>, whose overflow applies to the viewport.
+    if (style()->overflowX() != OVISIBLE && !isRootObject && (isRenderBlock() || isTableRow() || isTableSection())) {
+        bool boxHasOverflowClip = true;
+        if (isBody()) {
+            // Overflow on the body can propagate to the viewport under the following conditions.
+            // (1) The root element is <html>.
+            // (2) We are the primary <body> (can be checked by looking at document.body).
+            // (3) The root element has visible overflow.
+            if (document()->documentElement()->hasTagName(htmlTag) &&
+                document()->body() == node() &&
+                document()->documentElement()->renderer()->style()->overflowX() == OVISIBLE)
+                boxHasOverflowClip = false;
+        }
+        
+        // Check for overflow clip.
+        // It's sufficient to just check one direction, since it's illegal to have visible on only one overflow value.
+        if (boxHasOverflowClip) {
+            if (!s_hadOverflowClip)
+                // Erase the overflow
+                repaint();
+            setHasOverflowClip();
+        }
+    }
+
+    setHasTransform(style()->hasTransformRelatedProperty());
+    setHasReflection(style()->boxReflect());
+}
+
+void RenderBox::layout()
+{
+    ASSERT(needsLayout());
+
+    RenderObject* child = firstChild();
+    if (!child) {
+        setNeedsLayout(false);
+        return;
+    }
+
+    LayoutStateMaintainer statePusher(view(), this, locationOffset(), style()->isFlippedBlocksWritingMode());
+    while (child) {
+        child->layoutIfNeeded();
+        ASSERT(!child->needsLayout());
+        child = child->nextSibling();
+    }
+    statePusher.pop();
+    setNeedsLayout(false);
+}
+
+// More IE extensions.  clientWidth and clientHeight represent the interior of an object
+// excluding border and scrollbar.
+LayoutUnit RenderBox::clientWidth() const
+{
+    return width() - borderLeft() - borderRight() - verticalScrollbarWidth();
+}
+
+LayoutUnit RenderBox::clientHeight() const
+{
+    return height() - borderTop() - borderBottom() - horizontalScrollbarHeight();
+}
+
+int RenderBox::scrollWidth() const
+{
+    if (hasOverflowClip())
+        return layer()->scrollWidth();
+    // For objects with visible overflow, this matches IE.
+    // FIXME: Need to work right with writing modes.
+    if (style()->isLeftToRightDirection())
+        return max(clientWidth(), maxXLayoutOverflow() - borderLeft());
+    return clientWidth() - min(0, minXLayoutOverflow() - borderLeft());
+}
+
+int RenderBox::scrollHeight() const
+{
+    if (hasOverflowClip())
+        return layer()->scrollHeight();
+    // For objects with visible overflow, this matches IE.
+    // FIXME: Need to work right with writing modes.
+    return max(clientHeight(), maxYLayoutOverflow() - borderTop());
+}
+
+int RenderBox::scrollLeft() const
+{
+    return hasOverflowClip() ? layer()->scrollXOffset() : 0;
+}
+
+int RenderBox::scrollTop() const
+{
+    return hasOverflowClip() ? layer()->scrollYOffset() : 0;
+}
+
+void RenderBox::setScrollLeft(int newLeft)
+{
+    if (hasOverflowClip())
+        layer()->scrollToXOffset(newLeft, RenderLayer::ScrollOffsetClamped);
+}
+
+void RenderBox::setScrollTop(int newTop)
+{
+    if (hasOverflowClip())
+        layer()->scrollToYOffset(newTop, RenderLayer::ScrollOffsetClamped);
+}
+
+void RenderBox::absoluteRects(Vector<IntRect>& rects, const LayoutPoint& accumulatedOffset) const
+{
+    rects.append(LayoutRect(accumulatedOffset, size()));
+}
+
+void RenderBox::absoluteQuads(Vector<FloatQuad>& quads, bool* wasFixed) const
+{
+    quads.append(localToAbsoluteQuad(FloatRect(0, 0, width(), height()), false, wasFixed));
+}
+
+void RenderBox::updateLayerTransform()
+{
+    // Transform-origin depends on box size, so we need to update the layer transform after layout.
+    if (hasLayer())
+        layer()->updateTransform();
+}
+
+LayoutRect RenderBox::absoluteContentBox() const
+{
+    LayoutRect rect = contentBoxRect();
+    FloatPoint absPos = localToAbsolute(FloatPoint());
+    rect.move(absPos.x(), absPos.y());
+    return rect;
+}
+
+FloatQuad RenderBox::absoluteContentQuad() const
+{
+    LayoutRect rect = contentBoxRect();
+    return localToAbsoluteQuad(FloatRect(rect));
+}
+
+LayoutRect RenderBox::outlineBoundsForRepaint(RenderBoxModelObject* repaintContainer, LayoutPoint* cachedOffsetToRepaintContainer) const
+{
+    LayoutRect box = borderBoundingBox();
+    adjustRectForOutlineAndShadow(box);
+
+    FloatQuad containerRelativeQuad = FloatRect(box);
+    if (cachedOffsetToRepaintContainer)
+        containerRelativeQuad.move(cachedOffsetToRepaintContainer->x(), cachedOffsetToRepaintContainer->y());
+    else
+        containerRelativeQuad = localToContainerQuad(containerRelativeQuad, repaintContainer);
+
+    box = containerRelativeQuad.enclosingBoundingBox();
+
+    // FIXME: layoutDelta needs to be applied in parts before/after transforms and
+    // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
+    box.move(view()->layoutDelta());
+
+    return box;
+}
+
+void RenderBox::addFocusRingRects(Vector<LayoutRect>& rects, const LayoutPoint& additionalOffset)
+{
+    if (!size().isEmpty())
+        rects.append(LayoutRect(additionalOffset, size()));
+}
+
+LayoutRect RenderBox::reflectionBox() const
+{
+    LayoutRect result;
+    if (!style()->boxReflect())
+        return result;
+    LayoutRect box = borderBoxRect();
+    result = box;
+    switch (style()->boxReflect()->direction()) {
+        case ReflectionBelow:
+            result.move(0, box.height() + reflectionOffset());
+            break;
+        case ReflectionAbove:
+            result.move(0, -box.height() - reflectionOffset());
+            break;
+        case ReflectionLeft:
+            result.move(-box.width() - reflectionOffset(), 0);
+            break;
+        case ReflectionRight:
+            result.move(box.width() + reflectionOffset(), 0);
+            break;
+    }
+    return result;
+}
+
+int RenderBox::reflectionOffset() const
+{
+    if (!style()->boxReflect())
+        return 0;
+    if (style()->boxReflect()->direction() == ReflectionLeft || style()->boxReflect()->direction() == ReflectionRight)
+        return style()->boxReflect()->offset().calcValue(borderBoxRect().width());
+    return style()->boxReflect()->offset().calcValue(borderBoxRect().height());
+}
+
+LayoutRect RenderBox::reflectedRect(const LayoutRect& r) const
+{
+    if (!style()->boxReflect())
+        return LayoutRect();
+
+    LayoutRect box = borderBoxRect();
+    LayoutRect result = r;
+    switch (style()->boxReflect()->direction()) {
+        case ReflectionBelow:
+            result.setY(box.maxY() + reflectionOffset() + (box.maxY() - r.maxY()));
+            break;
+        case ReflectionAbove:
+            result.setY(box.y() - reflectionOffset() - box.height() + (box.maxY() - r.maxY()));
+            break;
+        case ReflectionLeft:
+            result.setX(box.x() - reflectionOffset() - box.width() + (box.maxX() - r.maxX()));
+            break;
+        case ReflectionRight:
+            result.setX(box.maxX() + reflectionOffset() + (box.maxX() - r.maxX()));
+            break;
+    }
+    return result;
+}
+
+bool RenderBox::shouldLayoutFixedElementRelativeToFrame(Frame* frame, FrameView* frameView) const
+{
+    return style() && style()->position() == FixedPosition && container()->isRenderView() && frame && frameView && frameView->shouldLayoutFixedElementsRelativeToFrame();
+}
+
+bool RenderBox::includeVerticalScrollbarSize() const
+{
+    return hasOverflowClip() && !layer()->hasOverlayScrollbars()
+        && (style()->overflowY() == OSCROLL || style()->overflowY() == OAUTO);
+}
+
+bool RenderBox::includeHorizontalScrollbarSize() const
+{
+    return hasOverflowClip() && !layer()->hasOverlayScrollbars()
+        && (style()->overflowX() == OSCROLL || style()->overflowX() == OAUTO);
+}
+
+int RenderBox::verticalScrollbarWidth() const
+{
+    return includeVerticalScrollbarSize() ? layer()->verticalScrollbarWidth() : 0;
+}
+
+int RenderBox::horizontalScrollbarHeight() const
+{
+    return includeHorizontalScrollbarSize() ? layer()->horizontalScrollbarHeight() : 0;
+}
+
+bool RenderBox::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier, Node** stopNode)
+{
+    RenderLayer* l = layer();
+    if (l && l->scroll(direction, granularity, multiplier)) {
+        if (stopNode)
+            *stopNode = node();
+        return true;
+    }
+
+    if (stopNode && *stopNode && *stopNode == node())
+        return true;
+
+    RenderBlock* b = containingBlock();
+    if (b && !b->isRenderView())
+        return b->scroll(direction, granularity, multiplier, stopNode);
+    return false;
+}
+
+bool RenderBox::logicalScroll(ScrollLogicalDirection direction, ScrollGranularity granularity, float multiplier, Node** stopNode)
+{
+    bool scrolled = false;
+    
+    RenderLayer* l = layer();
+    if (l) {
+#if PLATFORM(MAC)
+        // On Mac only we reset the inline direction position when doing a document scroll (e.g., hitting Home/End).
+        if (granularity == ScrollByDocument)
+            scrolled = l->scroll(logicalToPhysical(ScrollInlineDirectionBackward, isHorizontalWritingMode(), style()->isFlippedBlocksWritingMode()), ScrollByDocument, multiplier);
+#endif
+        if (l->scroll(logicalToPhysical(direction, isHorizontalWritingMode(), style()->isFlippedBlocksWritingMode()), granularity, multiplier))
+            scrolled = true;
+        
+        if (scrolled) {
+            if (stopNode)
+                *stopNode = node();
+            return true;
+        }
+    }
+
+    if (stopNode && *stopNode && *stopNode == node())
+        return true;
+
+    RenderBlock* b = containingBlock();
+    if (b && !b->isRenderView())
+        return b->logicalScroll(direction, granularity, multiplier, stopNode);
+    return false;
+}
+
+bool RenderBox::canBeScrolledAndHasScrollableArea() const
+{
+    return canBeProgramaticallyScrolled() && (scrollHeight() != clientHeight() || scrollWidth() != clientWidth());
+}
+    
+bool RenderBox::canBeProgramaticallyScrolled() const
+{
+    return (hasOverflowClip() && (scrollsOverflow() || (node() && node()->rendererIsEditable()))) || (node() && node()->isDocumentNode());
+}
+
+void RenderBox::autoscroll()
+{
+    if (layer())
+        layer()->autoscroll();
+}
+
+void RenderBox::panScroll(const IntPoint& source)
+{
+    if (layer())
+        layer()->panScrollFromPoint(source);
+}
+
+bool RenderBox::needsPreferredWidthsRecalculation() const
+{
+    return style()->paddingStart().isPercent() || style()->paddingEnd().isPercent();
+}
+
+LayoutUnit RenderBox::minPreferredLogicalWidth() const
+{
+    if (preferredLogicalWidthsDirty())
+        const_cast<RenderBox*>(this)->computePreferredLogicalWidths();
+        
+    return m_minPreferredLogicalWidth;
+}
+
+LayoutUnit RenderBox::maxPreferredLogicalWidth() const
+{
+    if (preferredLogicalWidthsDirty())
+        const_cast<RenderBox*>(this)->computePreferredLogicalWidths();
+        
+    return m_maxPreferredLogicalWidth;
+}
+
+bool RenderBox::hasOverrideHeight() const
+{
+    return gOverrideHeightMap && gOverrideHeightMap->contains(this);
+}
+
+bool RenderBox::hasOverrideWidth() const
+{
+    return gOverrideWidthMap && gOverrideWidthMap->contains(this);
+}
+
+void RenderBox::setOverrideHeight(LayoutUnit height)
+{
+    if (!gOverrideHeightMap)
+        gOverrideHeightMap = new OverrideSizeMap();
+    gOverrideHeightMap->set(this, height);
+}
+
+void RenderBox::setOverrideWidth(LayoutUnit width)
+{
+    if (!gOverrideWidthMap)
+        gOverrideWidthMap = new OverrideSizeMap();
+    gOverrideWidthMap->set(this, width);
+}
+
+void RenderBox::clearOverrideSize()
+{
+    if (hasOverrideHeight())
+        gOverrideHeightMap->remove(this);
+    if (hasOverrideWidth())
+        gOverrideWidthMap->remove(this);
+}
+
+LayoutUnit RenderBox::overrideWidth() const
+{
+    return hasOverrideWidth() ? gOverrideWidthMap->get(this) : width();
+}
+
+LayoutUnit RenderBox::overrideHeight() const
+{
+    return hasOverrideHeight() ? gOverrideHeightMap->get(this) : height();
+}
+
+LayoutUnit RenderBox::computeBorderBoxLogicalWidth(LayoutUnit width) const
+{
+    LayoutUnit bordersPlusPadding = borderAndPaddingLogicalWidth();
+    if (style()->boxSizing() == CONTENT_BOX)
+        return width + bordersPlusPadding;
+    return max(width, bordersPlusPadding);
+}
+
+LayoutUnit RenderBox::computeBorderBoxLogicalHeight(LayoutUnit height) const
+{
+    LayoutUnit bordersPlusPadding = borderAndPaddingLogicalHeight();
+    if (style()->boxSizing() == CONTENT_BOX)
+        return height + bordersPlusPadding;
+    return max(height, bordersPlusPadding);
+}
+
+LayoutUnit RenderBox::computeContentBoxLogicalWidth(LayoutUnit width) const
+{
+    if (style()->boxSizing() == BORDER_BOX)
+        width -= borderAndPaddingLogicalWidth();
+    return max<LayoutUnit>(0, width);
+}
+
+LayoutUnit RenderBox::computeContentBoxLogicalHeight(LayoutUnit height) const
+{
+    if (style()->boxSizing() == BORDER_BOX)
+        height -= borderAndPaddingLogicalHeight();
+    return max<LayoutUnit>(0, height);
+}
+
+// Hit Testing
+bool RenderBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const LayoutPoint& pointInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
+{
+    LayoutPoint adjustedLocation = accumulatedOffset + location();
+
+    // Check kids first.
+    for (RenderObject* child = lastChild(); child; child = child->previousSibling()) {
+        if (!child->hasLayer() && child->nodeAtPoint(request, result, pointInContainer, adjustedLocation, action)) {
+            updateHitTestResult(result, pointInContainer - toLayoutSize(adjustedLocation));
+            return true;
+        }
+    }
+
+    // Check our bounds next. For this purpose always assume that we can only be hit in the
+    // foreground phase (which is true for replaced elements like images).
+    LayoutRect boundsRect = borderBoxRectInRegion(result.region());
+    boundsRect.moveBy(adjustedLocation);
+    if (visibleToHitTesting() && action == HitTestForeground && boundsRect.intersects(result.rectForPoint(pointInContainer))) {
+        updateHitTestResult(result, pointInContainer - toLayoutSize(adjustedLocation));
+        if (!result.addNodeToRectBasedTestResult(node(), pointInContainer, boundsRect))
+            return true;
+    }
+
+    return false;
+}
+
+// --------------------- painting stuff -------------------------------
+
+void RenderBox::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    LayoutPoint adjustedPaintOffset = paintOffset + location();
+    // default implementation. Just pass paint through to the children
+    PaintInfo childInfo(paintInfo);
+    childInfo.updatePaintingRootForChildren(this);
+    for (RenderObject* child = firstChild(); child; child = child->nextSibling())
+        child->paint(childInfo, adjustedPaintOffset);
+}
+
+void RenderBox::paintRootBoxFillLayers(const PaintInfo& paintInfo)
+{
+    const FillLayer* bgLayer = style()->backgroundLayers();
+    Color bgColor = style()->visitedDependentColor(CSSPropertyBackgroundColor);
+    RenderObject* bodyObject = 0;
+    if (!hasBackground() && node() && node()->hasTagName(HTMLNames::htmlTag)) {
+        // Locate the <body> element using the DOM.  This is easier than trying
+        // to crawl around a render tree with potential :before/:after content and
+        // anonymous blocks created by inline <body> tags etc.  We can locate the <body>
+        // render object very easily via the DOM.
+        HTMLElement* body = document()->body();
+        bodyObject = (body && body->hasLocalName(bodyTag)) ? body->renderer() : 0;
+        if (bodyObject) {
+            bgLayer = bodyObject->style()->backgroundLayers();
+            bgColor = bodyObject->style()->visitedDependentColor(CSSPropertyBackgroundColor);
+        }
+    }
+
+    paintFillLayers(paintInfo, bgColor, bgLayer, view()->backgroundRect(this), BackgroundBleedNone, CompositeSourceOver, bodyObject);
+}
+
+BackgroundBleedAvoidance RenderBox::determineBackgroundBleedAvoidance(GraphicsContext* context) const
+{
+    if (context->paintingDisabled())
+        return BackgroundBleedNone;
+
+    const RenderStyle* style = this->style();
+
+    if (!style->hasBackground() || !style->hasBorder() || !style->hasBorderRadius() || borderImageIsLoadedAndCanBeRendered())
+        return BackgroundBleedNone;
+
+    AffineTransform ctm = context->getCTM();
+    FloatSize contextScaling(static_cast<float>(ctm.xScale()), static_cast<float>(ctm.yScale()));
+    if (borderObscuresBackgroundEdge(contextScaling))
+        return BackgroundBleedShrinkBackground;
+    
+    // FIXME: there is one more strategy possible, for opaque backgrounds and
+    // translucent borders. In that case we could avoid using a transparency layer,
+    // and paint the border first, and then paint the background clipped to the
+    // inside of the border.
+
+    return BackgroundBleedUseTransparencyLayer;
+}
+
+void RenderBox::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    if (!paintInfo.shouldPaintWithinRoot(this))
+        return;
+
+    LayoutRect paintRect = borderBoxRectInRegion(paintInfo.renderRegion);
+    paintRect.moveBy(paintOffset);
+
+    // border-fit can adjust where we paint our border and background.  If set, we snugly fit our line box descendants.  (The iChat
+    // balloon layout is an example of this).
+    borderFitAdjust(paintRect);
+
+    // FIXME: Should eventually give the theme control over whether the box shadow should paint, since controls could have
+    // custom shadows of their own.
+    paintBoxShadow(paintInfo, paintRect, style(), Normal);
+
+    BackgroundBleedAvoidance bleedAvoidance = determineBackgroundBleedAvoidance(paintInfo.context);
+
+    GraphicsContextStateSaver stateSaver(*paintInfo.context, false);
+    if (bleedAvoidance == BackgroundBleedUseTransparencyLayer) {
+        // To avoid the background color bleeding out behind the border, we'll render background and border
+        // into a transparency layer, and then clip that in one go (which requires setting up the clip before
+        // beginning the layer).
+        RoundedRect border = style()->getRoundedBorderFor(paintRect);
+        stateSaver.save();
+        paintInfo.context->addRoundedRectClip(border);
+        paintInfo.context->beginTransparencyLayer(1);
+    }
+    
+    // If we have a native theme appearance, paint that before painting our background.
+    // The theme will tell us whether or not we should also paint the CSS background.
+    bool themePainted = style()->hasAppearance() && !theme()->paint(this, paintInfo, paintRect);
+    if (!themePainted) {
+        paintBackground(paintInfo, paintRect, bleedAvoidance);
+
+        if (style()->hasAppearance())
+            theme()->paintDecorations(this, paintInfo, paintRect);
+    }
+    paintBoxShadow(paintInfo, paintRect, style(), Inset);
+
+    // The theme will tell us whether or not we should also paint the CSS border.
+    if ((!style()->hasAppearance() || (!themePainted && theme()->paintBorderOnly(this, paintInfo, paintRect))) && style()->hasBorder())
+        paintBorder(paintInfo, paintRect, style(), bleedAvoidance);
+
+    if (bleedAvoidance == BackgroundBleedUseTransparencyLayer)
+        paintInfo.context->endTransparencyLayer();
+}
+
+void RenderBox::paintBackground(const PaintInfo& paintInfo, const LayoutRect& paintRect, BackgroundBleedAvoidance bleedAvoidance)
+{
+    if (isRoot())
+        paintRootBoxFillLayers(paintInfo);
+    else if (!isBody() || (document()->documentElement()->renderer() && document()->documentElement()->renderer()->hasBackground())) {
+        // The <body> only paints its background if the root element has defined a background
+        // independent of the body.
+        if (!backgroundIsObscured())
+            paintFillLayers(paintInfo, style()->visitedDependentColor(CSSPropertyBackgroundColor), style()->backgroundLayers(), paintRect, bleedAvoidance);
+    }
+}
+
+void RenderBox::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    if (!paintInfo.shouldPaintWithinRoot(this) || style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask || paintInfo.context->paintingDisabled())
+        return;
+
+    LayoutRect paintRect = LayoutRect(paintOffset, size());
+
+    // border-fit can adjust where we paint our border and background.  If set, we snugly fit our line box descendants.  (The iChat
+    // balloon layout is an example of this).
+    borderFitAdjust(paintRect);
+
+    paintMaskImages(paintInfo, paintRect);
+}
+
+void RenderBox::paintMaskImages(const PaintInfo& paintInfo, const LayoutRect& paintRect)
+{
+    // Figure out if we need to push a transparency layer to render our mask.
+    bool pushTransparencyLayer = false;
+    bool compositedMask = hasLayer() && layer()->hasCompositedMask();
+    CompositeOperator compositeOp = CompositeSourceOver;
+
+    bool allMaskImagesLoaded = true;
+    
+    if (!compositedMask) {
+        // If the context has a rotation, scale or skew, then use a transparency layer to avoid
+        // pixel cruft around the edge of the mask.
+        const AffineTransform& currentCTM = paintInfo.context->getCTM();
+        pushTransparencyLayer = !currentCTM.isIdentityOrTranslationOrFlipped();
+
+        StyleImage* maskBoxImage = style()->maskBoxImage().image();
+        const FillLayer* maskLayers = style()->maskLayers();
+
+        // Don't render a masked element until all the mask images have loaded, to prevent a flash of unmasked content.
+        if (maskBoxImage)
+            allMaskImagesLoaded &= maskBoxImage->isLoaded();
+
+        if (maskLayers)
+            allMaskImagesLoaded &= maskLayers->imagesAreLoaded();
+
+        // Before all images have loaded, just use an empty transparency layer as the mask.
+        if (!allMaskImagesLoaded)
+            pushTransparencyLayer = true;
+
+        bool hasMaskLayerWithImage = maskLayers->hasImage();
+        if (maskBoxImage && hasMaskLayerWithImage) {
+            // We have a mask-box-image and mask-image, so need to composite them together before using the result as a mask.
+            pushTransparencyLayer = true;
+        } else if (hasMaskLayerWithImage) {
+            // We have to use an extra image buffer to hold the mask. Multiple mask images need
+            // to composite together using source-over so that they can then combine into a single unified mask that
+            // can be composited with the content using destination-in.  SVG images need to be able to set compositing modes
+            // as they draw images contained inside their sub-document, so we paint all our images into a separate buffer
+            // and composite that buffer as the mask.
+            // We have to check that the mask images to be rendered contain at least one image that can be actually used in rendering
+            // before pushing the transparency layer.
+            for (const FillLayer* fillLayer = maskLayers->next(); fillLayer; fillLayer = fillLayer->next()) {
+                if (fillLayer->image() && fillLayer->image()->canRender(this, style()->effectiveZoom())) {
+                    pushTransparencyLayer = true;
+                    // We found one image that can be used in rendering, exit the loop
+                    break;
+                }
+            }
+        }
+        
+        compositeOp = CompositeDestinationIn;
+        if (pushTransparencyLayer) {
+            paintInfo.context->setCompositeOperation(CompositeDestinationIn);
+            paintInfo.context->beginTransparencyLayer(1.0f);
+            compositeOp = CompositeSourceOver;
+        }
+    }
+
+    if (allMaskImagesLoaded) {
+        paintFillLayers(paintInfo, Color(), style()->maskLayers(), paintRect, BackgroundBleedNone, compositeOp);
+        paintNinePieceImage(paintInfo.context, paintRect, style(), style()->maskBoxImage(), compositeOp);
+    }
+    
+    if (pushTransparencyLayer)
+        paintInfo.context->endTransparencyLayer();
+}
+
+LayoutRect RenderBox::maskClipRect()
+{
+    const NinePieceImage& maskBoxImage = style()->maskBoxImage();
+    if (maskBoxImage.image()) {
+        LayoutRect borderImageRect = borderBoxRect();
+        
+        // Apply outsets to the border box.
+        LayoutUnit topOutset;
+        LayoutUnit rightOutset;
+        LayoutUnit bottomOutset;
+        LayoutUnit leftOutset;
+        style()->getMaskBoxImageOutsets(topOutset, rightOutset, bottomOutset, leftOutset);
+         
+        borderImageRect.setX(borderImageRect.x() - leftOutset);
+        borderImageRect.setY(borderImageRect.y() - topOutset);
+        borderImageRect.setWidth(borderImageRect.width() + leftOutset + rightOutset);
+        borderImageRect.setHeight(borderImageRect.height() + topOutset + bottomOutset);
+
+        return borderImageRect;
+    }
+    
+    LayoutRect result;
+    LayoutRect borderBox = borderBoxRect();
+    for (const FillLayer* maskLayer = style()->maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
+        if (maskLayer->image()) {
+            BackgroundImageGeometry geometry;
+            calculateBackgroundImageGeometry(maskLayer, borderBox, geometry);
+            result.unite(geometry.destRect());
+        }
+    }
+    return result;
+}
+
+void RenderBox::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect,
+    BackgroundBleedAvoidance bleedAvoidance, CompositeOperator op, RenderObject* backgroundObject)
+{
+    if (!fillLayer)
+        return;
+
+    paintFillLayers(paintInfo, c, fillLayer->next(), rect, bleedAvoidance, op, backgroundObject);
+    paintFillLayer(paintInfo, c, fillLayer, rect, bleedAvoidance, op, backgroundObject);
+}
+
+void RenderBox::paintFillLayer(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect,
+    BackgroundBleedAvoidance bleedAvoidance, CompositeOperator op, RenderObject* backgroundObject)
+{
+    paintFillLayerExtended(paintInfo, c, fillLayer, rect, bleedAvoidance, 0, IntSize(), op, backgroundObject);
+}
+
+#if USE(ACCELERATED_COMPOSITING)
+static bool layersUseImage(WrappedImagePtr image, const FillLayer* layers)
+{
+    for (const FillLayer* curLayer = layers; curLayer; curLayer = curLayer->next()) {
+        if (curLayer->image() && image == curLayer->image()->data())
+            return true;
+    }
+
+    return false;
+}
+#endif
+
+void RenderBox::imageChanged(WrappedImagePtr image, const IntRect*)
+{
+    if (!parent())
+        return;
+
+    if ((style()->borderImage().image() && style()->borderImage().image()->data() == image) ||
+        (style()->maskBoxImage().image() && style()->maskBoxImage().image()->data() == image)) {
+        repaint();
+        return;
+    }
+
+    bool didFullRepaint = repaintLayerRectsForImage(image, style()->backgroundLayers(), true);
+    if (!didFullRepaint)
+        repaintLayerRectsForImage(image, style()->maskLayers(), false);
+
+
+#if USE(ACCELERATED_COMPOSITING)
+    if (hasLayer() && layer()->hasCompositedMask() && layersUseImage(image, style()->maskLayers()))
+        layer()->contentChanged(RenderLayer::MaskImageChanged);
+#endif
+}
+
+bool RenderBox::repaintLayerRectsForImage(WrappedImagePtr image, const FillLayer* layers, bool drawingBackground)
+{
+    LayoutRect rendererRect;
+    RenderBox* layerRenderer = 0;
+
+    for (const FillLayer* curLayer = layers; curLayer; curLayer = curLayer->next()) {
+        if (curLayer->image() && image == curLayer->image()->data() && curLayer->image()->canRender(this, style()->effectiveZoom())) {
+            // Now that we know this image is being used, compute the renderer and the rect
+            // if we haven't already
+            if (!layerRenderer) {
+                bool drawingRootBackground = drawingBackground && (isRoot() || (isBody() && !document()->documentElement()->renderer()->hasBackground()));
+                if (drawingRootBackground) {
+                    layerRenderer = view();
+
+                    LayoutUnit rw;
+                    LayoutUnit rh;
+
+                    if (FrameView* frameView = toRenderView(layerRenderer)->frameView()) {
+                        rw = frameView->contentsWidth();
+                        rh = frameView->contentsHeight();
+                    } else {
+                        rw = layerRenderer->width();
+                        rh = layerRenderer->height();
+                    }
+                    rendererRect = LayoutRect(-layerRenderer->marginLeft(),
+                        -layerRenderer->marginTop(),
+                        max(layerRenderer->width() + layerRenderer->marginLeft() + layerRenderer->marginRight() + layerRenderer->borderLeft() + layerRenderer->borderRight(), rw),
+                        max(layerRenderer->height() + layerRenderer->marginTop() + layerRenderer->marginBottom() + layerRenderer->borderTop() + layerRenderer->borderBottom(), rh));
+                } else {
+                    layerRenderer = this;
+                    rendererRect = borderBoxRect();
+                }
+            }
+
+            BackgroundImageGeometry geometry;
+            layerRenderer->calculateBackgroundImageGeometry(curLayer, rendererRect, geometry);
+            layerRenderer->repaintRectangle(geometry.destRect());
+            if (geometry.destRect() == rendererRect)
+                return true;
+        }
+    }
+    return false;
+}
+
+#if PLATFORM(MAC)
+
+void RenderBox::paintCustomHighlight(const LayoutPoint& paintOffset, const AtomicString& type, bool behindText)
+{
+    Frame* frame = this->frame();
+    if (!frame)
+        return;
+    Page* page = frame->page();
+    if (!page)
+        return;
+
+    InlineBox* boxWrap = inlineBoxWrapper();
+    RootInlineBox* r = boxWrap ? boxWrap->root() : 0;
+    if (r) {
+        FloatRect rootRect(paintOffset.x() + r->x(), paintOffset.y() + r->selectionTop(), r->logicalWidth(), r->selectionHeight());
+        FloatRect imageRect(paintOffset.x() + x(), rootRect.y(), width(), rootRect.height());
+        page->chrome()->client()->paintCustomHighlight(node(), type, imageRect, rootRect, behindText, false);
+    } else {
+        FloatRect imageRect(paintOffset.x() + x(), paintOffset.y() + y(), width(), height());
+        page->chrome()->client()->paintCustomHighlight(node(), type, imageRect, imageRect, behindText, false);
+    }
+}
+
+#endif
+
+bool RenderBox::pushContentsClip(PaintInfo& paintInfo, const LayoutPoint& accumulatedOffset)
+{
+    if (paintInfo.phase == PaintPhaseBlockBackground || paintInfo.phase == PaintPhaseSelfOutline || paintInfo.phase == PaintPhaseMask)
+        return false;
+        
+    bool isControlClip = hasControlClip();
+    bool isOverflowClip = hasOverflowClip() && !layer()->isSelfPaintingLayer();
+    
+    if (!isControlClip && !isOverflowClip)
+        return false;
+    
+    if (paintInfo.phase == PaintPhaseOutline)
+        paintInfo.phase = PaintPhaseChildOutlines;
+    else if (paintInfo.phase == PaintPhaseChildBlockBackground) {
+        paintInfo.phase = PaintPhaseBlockBackground;
+        paintObject(paintInfo, accumulatedOffset);
+        paintInfo.phase = PaintPhaseChildBlockBackgrounds;
+    }
+    IntRect clipRect(isControlClip ? controlClipRect(accumulatedOffset) : overflowClipRect(accumulatedOffset, paintInfo.renderRegion));
+    paintInfo.context->save();
+    if (style()->hasBorderRadius())
+        paintInfo.context->addRoundedRectClip(style()->getRoundedInnerBorderFor(LayoutRect(accumulatedOffset, size())));
+    paintInfo.context->clip(clipRect);
+    return true;
+}
+
+void RenderBox::popContentsClip(PaintInfo& paintInfo, PaintPhase originalPhase, const LayoutPoint& accumulatedOffset)
+{
+    ASSERT(hasControlClip() || (hasOverflowClip() && !layer()->isSelfPaintingLayer()));
+
+    paintInfo.context->restore();
+    if (originalPhase == PaintPhaseOutline) {
+        paintInfo.phase = PaintPhaseSelfOutline;
+        paintObject(paintInfo, accumulatedOffset);
+        paintInfo.phase = originalPhase;
+    } else if (originalPhase == PaintPhaseChildBlockBackground)
+        paintInfo.phase = originalPhase;
+}
+
+LayoutRect RenderBox::overflowClipRect(const LayoutPoint& location, RenderRegion* region, OverlayScrollbarSizeRelevancy relevancy)
+{
+    // FIXME: When overflow-clip (CSS3) is implemented, we'll obtain the property
+    // here.
+    LayoutRect clipRect = borderBoxRectInRegion(region);
+    clipRect.setLocation(location + clipRect.location() + LayoutSize(borderLeft(), borderTop()));
+    clipRect.setSize(clipRect.size() - LayoutSize(borderLeft() + borderRight(), borderTop() + borderBottom()));
+
+    // Subtract out scrollbars if we have them.
+    if (layer())
+        clipRect.contract(layer()->verticalScrollbarWidth(relevancy), layer()->horizontalScrollbarHeight(relevancy));
+
+    return clipRect;
+}
+
+LayoutRect RenderBox::clipRect(const LayoutPoint& location, RenderRegion* region)
+{
+    LayoutRect borderBoxRect = borderBoxRectInRegion(region);
+    LayoutRect clipRect = LayoutRect(borderBoxRect.location() + location, borderBoxRect.size());
+
+    if (!style()->clipLeft().isAuto()) {
+        LayoutUnit c = style()->clipLeft().calcValue(borderBoxRect.width());
+        clipRect.move(c, 0);
+        clipRect.contract(c, 0);
+    }
+
+    // We don't use the region-specific border box's width and height since clip offsets are (stupidly) specified
+    // from the left and top edges. Therefore it's better to avoid constraining to smaller widths and heights.
+
+    if (!style()->clipRight().isAuto())
+        clipRect.contract(width() - style()->clipRight().calcValue(width()), 0);
+
+    if (!style()->clipTop().isAuto()) {
+        LayoutUnit c = style()->clipTop().calcValue(borderBoxRect.height());
+        clipRect.move(0, c);
+        clipRect.contract(0, c);
+    }
+
+    if (!style()->clipBottom().isAuto())
+        clipRect.contract(0, height() - style()->clipBottom().calcValue(height()));
+
+    return clipRect;
+}
+
+LayoutUnit RenderBox::containingBlockLogicalWidthForContent() const
+{
+    RenderBlock* cb = containingBlock();
+    if (shrinkToAvoidFloats() && !inRenderFlowThread())
+        return cb->availableLogicalWidthForLine(logicalTop(), false);
+    return cb->availableLogicalWidth();
+}
+
+LayoutUnit RenderBox::containingBlockLogicalWidthForContentInRegion(RenderRegion* region, LayoutUnit offsetFromLogicalTopOfFirstPage) const
+{
+    if (!region)
+        return containingBlockLogicalWidthForContent();
+
+    RenderBlock* cb = containingBlock();
+    RenderRegion* containingBlockRegion = cb->clampToStartAndEndRegions(region);
+    if (shrinkToAvoidFloats()) {
+        LayoutUnit offsetFromLogicalTopOfRegion = region->offsetFromLogicalTopOfFirstPage() - offsetFromLogicalTopOfFirstPage;
+        return cb->availableLogicalWidthForLine(max(logicalTop(), logicalTop() + offsetFromLogicalTopOfRegion), false, containingBlockRegion, offsetFromLogicalTopOfFirstPage - logicalTop());
+    }
+    LayoutUnit result = cb->availableLogicalWidth();
+    RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(containingBlockRegion, offsetFromLogicalTopOfFirstPage - logicalTop());
+    if (!boxInfo)
+        return result;
+    return max<LayoutUnit>(0, result - (cb->logicalWidth() - boxInfo->logicalWidth()));
+}
+
+LayoutUnit RenderBox::perpendicularContainingBlockLogicalHeight() const
+{
+    RenderBlock* cb = containingBlock();
+    RenderStyle* containingBlockStyle = cb->style();
+    Length logicalHeightLength = containingBlockStyle->logicalHeight();
+    
+    // FIXME: For now just support fixed heights.  Eventually should support percentage heights as well.
+    if (!logicalHeightLength.isFixed()) {
+        // Rather than making the child be completely unconstrained, WinIE uses the viewport width and height
+        // as a constraint.  We do that for now as well even though it's likely being unconstrained is what the spec
+        // will decide.
+        return containingBlockStyle->isHorizontalWritingMode() ? view()->frameView()->visibleHeight() : view()->frameView()->visibleWidth();
+    }
+    
+    // Use the content box logical height as specified by the style.
+    return cb->computeContentBoxLogicalHeight(logicalHeightLength.value());
+}
+
+void RenderBox::mapLocalToContainer(RenderBoxModelObject* repaintContainer, bool fixed, bool useTransforms, TransformState& transformState, bool* wasFixed) const
+{
+    if (repaintContainer == this)
+        return;
+
+    if (RenderView* v = view()) {
+        if (v->layoutStateEnabled() && !repaintContainer) {
+            LayoutState* layoutState = v->layoutState();
+            LayoutSize offset = layoutState->m_paintOffset;
+            offset.expand(x(), y());
+            if (style()->position() == RelativePosition && layer())
+                offset += layer()->relativePositionOffset();
+            transformState.move(offset);
+            return;
+        }
+    }
+
+    bool containerSkipped;
+    RenderObject* o = container(repaintContainer, &containerSkipped);
+    if (!o)
+        return;
+
+    bool isFixedPos = style()->position() == FixedPosition;
+    bool hasTransform = hasLayer() && layer()->transform();
+    if (hasTransform) {
+        // If this box has a transform, it acts as a fixed position container for fixed descendants,
+        // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
+        fixed &= isFixedPos;
+    } else
+        fixed |= isFixedPos;
+    if (wasFixed)
+        *wasFixed = fixed;
+    
+    LayoutSize containerOffset = offsetFromContainer(o, roundedLayoutPoint(transformState.mappedPoint()));
+    
+    bool preserve3D = useTransforms && (o->style()->preserves3D() || style()->preserves3D());
+    if (useTransforms && shouldUseTransformFromContainer(o)) {
+        TransformationMatrix t;
+        getTransformFromContainer(o, containerOffset, t);
+        transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
+    } else
+        transformState.move(containerOffset.width(), containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
+
+    if (containerSkipped) {
+        // There can't be a transform between repaintContainer and o, because transforms create containers, so it should be safe
+        // to just subtract the delta between the repaintContainer and o.
+        LayoutSize containerOffset = repaintContainer->offsetFromAncestorContainer(o);
+        transformState.move(-containerOffset.width(), -containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
+        return;
+    }
+
+    if (o->isRenderFlowThread()) {
+        // Transform from render flow coordinates into region coordinates.
+        RenderRegion* region = toRenderFlowThread(o)->mapFromFlowToRegion(transformState);
+        if (region)
+            region->mapLocalToContainer(region->containerForRepaint(), fixed, useTransforms, transformState, wasFixed);
+        return;
+    }
+
+    o->mapLocalToContainer(repaintContainer, fixed, useTransforms, transformState, wasFixed);
+}
+
+void RenderBox::mapAbsoluteToLocalPoint(bool fixed, bool useTransforms, TransformState& transformState) const
+{
+    // We don't expect absoluteToLocal() to be called during layout (yet)
+    ASSERT(!view() || !view()->layoutStateEnabled());
+    
+    bool isFixedPos = style()->position() == FixedPosition;
+    bool hasTransform = hasLayer() && layer()->transform();
+    if (hasTransform) {
+        // If this box has a transform, it acts as a fixed position container for fixed descendants,
+        // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
+        fixed &= isFixedPos;
+    } else
+        fixed |= isFixedPos;
+
+    RenderBoxModelObject::mapAbsoluteToLocalPoint(fixed, useTransforms, transformState);
+}
+
+LayoutSize RenderBox::offsetFromContainer(RenderObject* o, const LayoutPoint& point) const
+{
+    ASSERT(o == container());
+
+    LayoutSize offset;    
+    if (isRelPositioned())
+        offset += relativePositionOffset();
+
+    if (!isInline() || isReplaced()) {
+        if (style()->position() != AbsolutePosition && style()->position() != FixedPosition && o->hasColumns()) {
+            RenderBlock* block = toRenderBlock(o);
+            LayoutRect columnRect(frameRect());
+            block->adjustStartEdgeForWritingModeIncludingColumns(columnRect);
+            offset += toSize(columnRect.location());
+            LayoutPoint columnPoint = block->flipForWritingModeIncludingColumns(point + offset);
+            offset = toLayoutSize(block->flipForWritingModeIncludingColumns(toLayoutPoint(offset)));
+            o->adjustForColumns(offset, columnPoint);
+            offset = block->flipForWritingMode(offset);
+        } else
+            offset += topLeftLocationOffset();
+    }
+
+    if (o->hasOverflowClip())
+        offset -= toRenderBox(o)->layer()->scrolledContentOffset();
+
+    if (style()->position() == AbsolutePosition && o->isRelPositioned() && o->isRenderInline())
+        offset += toRenderInline(o)->relativePositionedInlineOffset(this);
+
+    return offset;
+}
+
+InlineBox* RenderBox::createInlineBox()
+{
+    return new (renderArena()) InlineBox(this);
+}
+
+void RenderBox::dirtyLineBoxes(bool fullLayout)
+{
+    if (m_inlineBoxWrapper) {
+        if (fullLayout) {
+            m_inlineBoxWrapper->destroy(renderArena());
+            m_inlineBoxWrapper = 0;
+        } else
+            m_inlineBoxWrapper->dirtyLineBoxes();
+    }
+}
+
+void RenderBox::positionLineBox(InlineBox* box)
+{
+    if (isPositioned()) {
+        // Cache the x position only if we were an INLINE type originally.
+        bool wasInline = style()->isOriginalDisplayInlineType();
+        if (wasInline) {
+            // The value is cached in the xPos of the box.  We only need this value if
+            // our object was inline originally, since otherwise it would have ended up underneath
+            // the inlines.
+            RootInlineBox* root = box->root();
+            root->block()->setStaticInlinePositionForChild(this, root->lineTopWithLeading(), lroundf(box->logicalLeft()));
+            if (style()->hasStaticInlinePosition(box->isHorizontal()))
+                setChildNeedsLayout(true, false); // Just go ahead and mark the positioned object as needing layout, so it will update its position properly.
+        } else {
+            // Our object was a block originally, so we make our normal flow position be
+            // just below the line box (as though all the inlines that came before us got
+            // wrapped in an anonymous block, which is what would have happened had we been
+            // in flow).  This value was cached in the y() of the box.
+            layer()->setStaticBlockPosition(box->logicalTop());
+            if (style()->hasStaticBlockPosition(box->isHorizontal()))
+                setChildNeedsLayout(true, false); // Just go ahead and mark the positioned object as needing layout, so it will update its position properly.
+        }
+
+        // Nuke the box.
+        box->remove();
+        box->destroy(renderArena());
+    } else if (isReplaced()) {
+        setLocation(roundedLayoutPoint(box->topLeft()));
+        // m_inlineBoxWrapper should already be 0. Deleting it is a safeguard against security issues.
+        ASSERT(!m_inlineBoxWrapper);
+        if (m_inlineBoxWrapper)
+            deleteLineBoxWrapper();
+        m_inlineBoxWrapper = box;
+    }
+}
+
+void RenderBox::deleteLineBoxWrapper()
+{
+    if (m_inlineBoxWrapper) {
+        if (!documentBeingDestroyed())
+            m_inlineBoxWrapper->remove();
+        m_inlineBoxWrapper->destroy(renderArena());
+        m_inlineBoxWrapper = 0;
+    }
+}
+
+LayoutRect RenderBox::clippedOverflowRectForRepaint(RenderBoxModelObject* repaintContainer) const
+{
+    if (style()->visibility() != VISIBLE && !enclosingLayer()->hasVisibleContent())
+        return LayoutRect();
+
+    LayoutRect r = visualOverflowRect();
+
+    RenderView* v = view();
+    if (v) {
+        // FIXME: layoutDelta needs to be applied in parts before/after transforms and
+        // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
+        r.move(v->layoutDelta());
+    }
+    
+    if (style()) {
+        // We have to use maximalOutlineSize() because a child might have an outline
+        // that projects outside of our overflowRect.
+        if (v) {
+            ASSERT(style()->outlineSize() <= v->maximalOutlineSize());
+            r.inflate(v->maximalOutlineSize());
+        }
+    }
+    
+    computeRectForRepaint(repaintContainer, r);
+    return r;
+}
+
+void RenderBox::computeRectForRepaint(RenderBoxModelObject* repaintContainer, LayoutRect& rect, bool fixed) const
+{
+    // The rect we compute at each step is shifted by our x/y offset in the parent container's coordinate space.
+    // Only when we cross a writing mode boundary will we have to possibly flipForWritingMode (to convert into a more appropriate
+    // offset corner for the enclosing container).  This allows for a fully RL or BT document to repaint
+    // properly even during layout, since the rect remains flipped all the way until the end.
+    //
+    // RenderView::computeRectForRepaint then converts the rect to physical coordinates.  We also convert to
+    // physical when we hit a repaintContainer boundary.  Therefore the final rect returned is always in the
+    // physical coordinate space of the repaintContainer.
+    if (RenderView* v = view()) {
+        // LayoutState is only valid for root-relative, non-fixed position repainting
+        if (v->layoutStateEnabled() && !repaintContainer && style()->position() != FixedPosition) {
+            LayoutState* layoutState = v->layoutState();
+
+            if (layer() && layer()->transform())
+                rect = layer()->transform()->mapRect(rect);
+
+            if (style()->position() == RelativePosition && layer())
+                rect.move(layer()->relativePositionOffset());
+
+            rect.moveBy(location());
+            rect.move(layoutState->m_paintOffset);
+            if (layoutState->m_clipped)
+                rect.intersect(layoutState->m_clipRect);
+            return;
+        }
+    }
+
+    if (hasReflection())
+        rect.unite(reflectedRect(rect));
+
+    if (repaintContainer == this) {
+        if (repaintContainer->style()->isFlippedBlocksWritingMode())
+            flipForWritingMode(rect);
+        return;
+    }
+
+    bool containerSkipped;
+    RenderObject* o = container(repaintContainer, &containerSkipped);
+    if (!o)
+        return;
+
+    if (isWritingModeRoot() && !isPositioned())
+        flipForWritingMode(rect);
+
+#if ENABLE(CSS_FILTERS)
+    if (style()->hasFilterOutsets()) {
+        LayoutUnit topOutset;
+        LayoutUnit rightOutset;
+        LayoutUnit bottomOutset;
+        LayoutUnit leftOutset;
+        style()->filter().getOutsets(topOutset, rightOutset, bottomOutset, leftOutset);
+        rect.move(-leftOutset, -topOutset);
+        rect.expand(leftOutset + rightOutset, topOutset + bottomOutset);
+    }
+#endif
+
+    LayoutPoint topLeft = rect.location();
+    topLeft.move(x(), y());
+
+    EPosition position = style()->position();
+
+    // We are now in our parent container's coordinate space.  Apply our transform to obtain a bounding box
+    // in the parent's coordinate space that encloses us.
+    if (layer() && layer()->transform()) {
+        fixed = position == FixedPosition;
+        rect = layer()->transform()->mapRect(rect);
+        topLeft = rect.location();
+        topLeft.move(x(), y());
+    } else if (position == FixedPosition)
+        fixed = true;
+
+    if (position == AbsolutePosition && o->isRelPositioned() && o->isRenderInline())
+        topLeft += toRenderInline(o)->relativePositionedInlineOffset(this);
+    else if (position == RelativePosition && layer()) {
+        // Apply the relative position offset when invalidating a rectangle.  The layer
+        // is translated, but the render box isn't, so we need to do this to get the
+        // right dirty rect.  Since this is called from RenderObject::setStyle, the relative position
+        // flag on the RenderObject has been cleared, so use the one on the style().
+        topLeft += layer()->relativePositionOffset();
+    }
+    
+    if (o->isBlockFlow() && position != AbsolutePosition && position != FixedPosition) {
+        RenderBlock* cb = toRenderBlock(o);
+        if (cb->hasColumns()) {
+            LayoutRect repaintRect(topLeft, rect.size());
+            cb->adjustRectForColumns(repaintRect);
+            topLeft = repaintRect.location();
+            rect = repaintRect;
+        }
+    }
+
+    // FIXME: We ignore the lightweight clipping rect that controls use, since if |o| is in mid-layout,
+    // its controlClipRect will be wrong. For overflow clip we use the values cached by the layer.
+    if (o->hasOverflowClip()) {
+        RenderBox* containerBox = toRenderBox(o);
+
+        // o->height() is inaccurate if we're in the middle of a layout of |o|, so use the
+        // layer's size instead.  Even if the layer's size is wrong, the layer itself will repaint
+        // anyway if its size does change.
+        topLeft -= containerBox->layer()->scrolledContentOffset(); // For overflow:auto/scroll/hidden.
+
+        LayoutRect repaintRect(topLeft, rect.size());
+        LayoutRect boxRect(LayoutPoint(), containerBox->layer()->size());
+        rect = intersection(repaintRect, boxRect);
+        if (rect.isEmpty())
+            return;
+    } else
+        rect.setLocation(topLeft);
+
+    if (containerSkipped) {
+        // If the repaintContainer is below o, then we need to map the rect into repaintContainer's coordinates.
+        LayoutSize containerOffset = repaintContainer->offsetFromAncestorContainer(o);
+        rect.move(-containerOffset);
+        return;
+    }
+
+    o->computeRectForRepaint(repaintContainer, rect, fixed);
+}
+
+void RenderBox::repaintDuringLayoutIfMoved(const LayoutRect& rect)
+{
+    LayoutUnit newX = x();
+    LayoutUnit newY = y();
+    LayoutUnit newWidth = width();
+    LayoutUnit newHeight = height();
+    if (rect.x() != newX || rect.y() != newY) {
+        // The child moved.  Invalidate the object's old and new positions.  We have to do this
+        // since the object may not have gotten a layout.
+        m_frameRect = rect;
+        repaint();
+        repaintOverhangingFloats(true);
+        m_frameRect = LayoutRect(newX, newY, newWidth, newHeight);
+        repaint();
+        repaintOverhangingFloats(true);
+    }
+}
+
+void RenderBox::computeLogicalWidth()
+{
+    computeLogicalWidthInRegion();
+}
+
+void RenderBox::computeLogicalWidthInRegion(RenderRegion* region, LayoutUnit offsetFromLogicalTopOfFirstPage)
+{
+    if (isPositioned()) {
+        // FIXME: This calculation is not patched for block-flow yet.
+        // https://bugs.webkit.org/show_bug.cgi?id=46500
+        computePositionedLogicalWidth(region, offsetFromLogicalTopOfFirstPage);
+        return;
+    }
+
+    // If layout is limited to a subtree, the subtree root's logical width does not change.
+    if (node() && view()->frameView() && view()->frameView()->layoutRoot(true) == this)
+        return;
+
+    // The parent box is flexing us, so it has increased or decreased our
+    // width.  Use the width from the style context.
+    // FIXME: Account for block-flow in flexible boxes.
+    // https://bugs.webkit.org/show_bug.cgi?id=46418
+    if (hasOverrideWidth() && parent()->isFlexibleBoxIncludingDeprecated()) {
+        setLogicalWidth(overrideWidth());
+        return;
+    }
+
+    // FIXME: Account for block-flow in flexible boxes.
+    // https://bugs.webkit.org/show_bug.cgi?id=46418
+    bool inVerticalBox = parent()->isDeprecatedFlexibleBox() && (parent()->style()->boxOrient() == VERTICAL);
+    bool stretching = (parent()->style()->boxAlign() == BSTRETCH);
+    bool treatAsReplaced = shouldComputeSizeAsReplaced() && (!inVerticalBox || !stretching);
+
+    Length logicalWidthLength = (treatAsReplaced) ? Length(computeReplacedLogicalWidth(), Fixed) : style()->logicalWidth();
+
+    RenderBlock* cb = containingBlock();
+    LayoutUnit containerLogicalWidth = max<LayoutUnit>(0, containingBlockLogicalWidthForContentInRegion(region, offsetFromLogicalTopOfFirstPage));
+    bool hasPerpendicularContainingBlock = cb->isHorizontalWritingMode() != isHorizontalWritingMode();
+    LayoutUnit containerWidthInInlineDirection = containerLogicalWidth;
+    if (hasPerpendicularContainingBlock)
+        containerWidthInInlineDirection = perpendicularContainingBlockLogicalHeight();
+    
+    if (isInline() && !isInlineBlockOrInlineTable()) {
+        // just calculate margins
+        setMarginStart(style()->marginStart().calcMinValue(containerLogicalWidth));
+        setMarginEnd(style()->marginEnd().calcMinValue(containerLogicalWidth));
+        if (treatAsReplaced)
+            setLogicalWidth(max<LayoutUnit>(logicalWidthLength.calcFloatValue(0) + borderAndPaddingLogicalWidth(), minPreferredLogicalWidth()));
+        return;
+    }
+
+    // Width calculations
+    if (treatAsReplaced)
+        setLogicalWidth(logicalWidthLength.value() + borderAndPaddingLogicalWidth());
+    else {
+        // Calculate LogicalWidth
+        setLogicalWidth(computeLogicalWidthUsing(LogicalWidth, containerWidthInInlineDirection));
+
+        // Calculate MaxLogicalWidth
+        if (!style()->logicalMaxWidth().isUndefined()) {
+            LayoutUnit maxLogicalWidth = computeLogicalWidthUsing(MaxLogicalWidth, containerWidthInInlineDirection);
+            if (logicalWidth() > maxLogicalWidth) {
+                setLogicalWidth(maxLogicalWidth);
+                logicalWidthLength = style()->logicalMaxWidth();
+            }
+        }
+
+        // Calculate MinLogicalWidth
+        LayoutUnit minLogicalWidth = computeLogicalWidthUsing(MinLogicalWidth, containerWidthInInlineDirection);
+        if (logicalWidth() < minLogicalWidth) {
+            setLogicalWidth(minLogicalWidth);
+            logicalWidthLength = style()->logicalMinWidth();
+        }
+    }
+
+    // Fieldsets are currently the only objects that stretch to their minimum width.
+    if (stretchesToMinIntrinsicLogicalWidth()) {
+        setLogicalWidth(max(logicalWidth(), minPreferredLogicalWidth()));
+        logicalWidthLength = Length(logicalWidth(), Fixed);
+    }
+
+    // Margin calculations.
+    if (logicalWidthLength.isAuto() || hasPerpendicularContainingBlock) {
+        setMarginStart(style()->marginStart().calcMinValue(containerLogicalWidth));
+        setMarginEnd(style()->marginEnd().calcMinValue(containerLogicalWidth));
+    } else
+        computeInlineDirectionMargins(cb, containerLogicalWidth, logicalWidth());
+
+    if (!hasPerpendicularContainingBlock && containerLogicalWidth && containerLogicalWidth != (logicalWidth() + marginStart() + marginEnd())
+            && !isFloating() && !isInline() && !cb->isFlexibleBoxIncludingDeprecated())
+        cb->setMarginEndForChild(this, containerLogicalWidth - logicalWidth() - cb->marginStartForChild(this));
+}
+
+LayoutUnit RenderBox::computeLogicalWidthUsing(LogicalWidthType widthType, LayoutUnit availableLogicalWidth)
+{
+    LayoutUnit logicalWidthResult = logicalWidth();
+    Length logicalWidth;
+    if (widthType == LogicalWidth)
+        logicalWidth = style()->logicalWidth();
+    else if (widthType == MinLogicalWidth)
+        logicalWidth = style()->logicalMinWidth();
+    else
+        logicalWidth = style()->logicalMaxWidth();
+
+    if (logicalWidth.isIntrinsicOrAuto()) {
+        LayoutUnit marginStart = style()->marginStart().calcMinValue(availableLogicalWidth);
+        LayoutUnit marginEnd = style()->marginEnd().calcMinValue(availableLogicalWidth);
+        logicalWidthResult = availableLogicalWidth - marginStart - marginEnd;
+
+        if (sizesToIntrinsicLogicalWidth(widthType)) {
+            logicalWidthResult = max(logicalWidthResult, minPreferredLogicalWidth());
+            logicalWidthResult = min(logicalWidthResult, maxPreferredLogicalWidth());
+        }
+    } else // FIXME: If the containing block flow is perpendicular to our direction we need to use the available logical height instead.
+        logicalWidthResult = computeBorderBoxLogicalWidth(logicalWidth.calcValue(availableLogicalWidth)); 
+
+    return logicalWidthResult;
+}
+
+bool RenderBox::sizesToIntrinsicLogicalWidth(LogicalWidthType widthType) const
+{
+    // Marquees in WinIE are like a mixture of blocks and inline-blocks.  They size as though they're blocks,
+    // but they allow text to sit on the same line as the marquee.
+    if (isFloating() || (isInlineBlockOrInlineTable() && !isHTMLMarquee()))
+        return true;
+
+    // This code may look a bit strange.  Basically width:intrinsic should clamp the size when testing both
+    // min-width and width.  max-width is only clamped if it is also intrinsic.
+    Length logicalWidth = (widthType == MaxLogicalWidth) ? style()->logicalMaxWidth() : style()->logicalWidth();
+    if (logicalWidth.type() == Intrinsic)
+        return true;
+
+    // Children of a horizontal marquee do not fill the container by default.
+    // FIXME: Need to deal with MAUTO value properly.  It could be vertical.
+    // FIXME: Think about block-flow here.  Need to find out how marquee direction relates to
+    // block-flow (as well as how marquee overflow should relate to block flow).
+    // https://bugs.webkit.org/show_bug.cgi?id=46472
+    if (parent()->style()->overflowX() == OMARQUEE) {
+        EMarqueeDirection dir = parent()->style()->marqueeDirection();
+        if (dir == MAUTO || dir == MFORWARD || dir == MBACKWARD || dir == MLEFT || dir == MRIGHT)
+            return true;
+    }
+
+    // Flexible box items should shrink wrap, so we lay them out at their intrinsic widths.
+    // In the case of columns that have a stretch alignment, we go ahead and layout at the
+    // stretched size to avoid an extra layout when applying alignment.
+    if (parent()->isFlexibleBox() && (!parent()->style()->isColumnFlexDirection() || style()->flexAlign() != AlignStretch))
+        return true;
+
+    // Flexible horizontal boxes lay out children at their intrinsic widths.  Also vertical boxes
+    // that don't stretch their kids lay out their children at their intrinsic widths.
+    // FIXME: Think about block-flow here.
+    // https://bugs.webkit.org/show_bug.cgi?id=46473
+    if (parent()->isDeprecatedFlexibleBox()
+            && (parent()->style()->boxOrient() == HORIZONTAL || parent()->style()->boxAlign() != BSTRETCH))
+        return true;
+
+    // Button, input, select, textarea, and legend treat
+    // width value of 'auto' as 'intrinsic' unless it's in a
+    // stretching vertical flexbox.
+    // FIXME: Think about block-flow here.
+    // https://bugs.webkit.org/show_bug.cgi?id=46473
+    if (logicalWidth.type() == Auto && !(parent()->isDeprecatedFlexibleBox() && parent()->style()->boxOrient() == VERTICAL && parent()->style()->boxAlign() == BSTRETCH) && node() && (node()->hasTagName(inputTag) || node()->hasTagName(selectTag) || node()->hasTagName(buttonTag) || node()->hasTagName(textareaTag) || node()->hasTagName(legendTag)))
+        return true;
+
+    if (isHorizontalWritingMode() != containingBlock()->isHorizontalWritingMode())
+        return true;
+
+    return false;
+}
+
+void RenderBox::computeInlineDirectionMargins(RenderBlock* containingBlock, LayoutUnit containerWidth, LayoutUnit childWidth)
+{
+    const RenderStyle* containingBlockStyle = containingBlock->style();
+    Length marginStartLength = style()->marginStartUsing(containingBlockStyle);
+    Length marginEndLength = style()->marginEndUsing(containingBlockStyle);
+
+    if (isFloating() || isInline()) {
+        // Inline blocks/tables and floats don't have their margins increased.
+        containingBlock->setMarginStartForChild(this, marginStartLength.calcMinValue(containerWidth));
+        containingBlock->setMarginEndForChild(this, marginEndLength.calcMinValue(containerWidth));
+        return;
+    }
+
+    // Case One: The object is being centered in the containing block's available logical width.
+    if ((marginStartLength.isAuto() && marginEndLength.isAuto() && childWidth < containerWidth)
+        || (!marginStartLength.isAuto() && !marginEndLength.isAuto() && containingBlock->style()->textAlign() == WEBKIT_CENTER)) {
+        containingBlock->setMarginStartForChild(this, max<LayoutUnit>(0, (containerWidth - childWidth) / 2));
+        containingBlock->setMarginEndForChild(this, containerWidth - childWidth - containingBlock->marginStartForChild(this));
+        return;
+    } 
+    
+    // Case Two: The object is being pushed to the start of the containing block's available logical width.
+    if (marginEndLength.isAuto() && childWidth < containerWidth) {
+        containingBlock->setMarginStartForChild(this, marginStartLength.calcValue(containerWidth));
+        containingBlock->setMarginEndForChild(this, containerWidth - childWidth - containingBlock->marginStartForChild(this));
+        return;
+    } 
+    
+    // Case Three: The object is being pushed to the end of the containing block's available logical width.
+    bool pushToEndFromTextAlign = !marginEndLength.isAuto() && ((!containingBlockStyle->isLeftToRightDirection() && containingBlockStyle->textAlign() == WEBKIT_LEFT)
+        || (containingBlockStyle->isLeftToRightDirection() && containingBlockStyle->textAlign() == WEBKIT_RIGHT));
+    if ((marginStartLength.isAuto() && childWidth < containerWidth) || pushToEndFromTextAlign) {
+        containingBlock->setMarginEndForChild(this, marginEndLength.calcValue(containerWidth));
+        containingBlock->setMarginStartForChild(this, containerWidth - childWidth - containingBlock->marginEndForChild(this));
+        return;
+    } 
+    
+    // Case Four: Either no auto margins, or our width is >= the container width (css2.1, 10.3.3).  In that case
+    // auto margins will just turn into 0.
+    containingBlock->setMarginStartForChild(this, marginStartLength.calcMinValue(containerWidth));
+    containingBlock->setMarginEndForChild(this, marginEndLength.calcMinValue(containerWidth));
+}
+
+RenderBoxRegionInfo* RenderBox::renderBoxRegionInfo(RenderRegion* region, LayoutUnit offsetFromLogicalTopOfFirstPage, RenderBoxRegionInfoFlags cacheFlag) const
+{
+    // Make sure nobody is trying to call this with a null region.
+    if (!region)
+        return 0;
+
+    // If we have computed our width in this region already, it will be cached, and we can
+    // just return it.
+    RenderBoxRegionInfo* boxInfo = region->renderBoxRegionInfo(this);
+    if (boxInfo && cacheFlag == CacheRenderBoxRegionInfo)
+        return boxInfo;
+
+    // No cached value was found, so we have to compute our insets in this region.
+    // FIXME: For now we limit this computation to normal RenderBlocks. Future patches will expand
+    // support to cover all boxes.
+    if (!inRenderFlowThread() || isFloating() || isReplaced() || isInline() || hasColumns()
+        || isTableCell() || !isBlockFlow() || isRenderFlowThread())
+        return 0;
+
+    // FIXME: It's gross to cast away the const, but it would be a huge refactoring to
+    // change all width computation to avoid updating any member variables, and it would be pretty lame to
+    // make all the variables mutable as well.
+    RenderFlowThread* flowThread = enclosingRenderFlowThread();
+    if (flowThread->style()->writingMode() != style()->writingMode())
+        return 0;
+
+    LayoutUnit oldLogicalWidth = logicalWidth();
+    LayoutUnit oldLogicalLeft = logicalLeft();
+    LayoutUnit oldMarginStart = marginStart();
+    LayoutUnit oldMarginEnd = marginEnd();
+
+    RenderBox* mutableBox = const_cast<RenderBox*>(this);
+    
+    mutableBox->computeLogicalWidthInRegion(region, offsetFromLogicalTopOfFirstPage);
+
+    // Now determine the insets based off where this object is supposed to be positioned.
+    RenderBlock* cb = containingBlock();
+    RenderRegion* clampedContainingBlockRegion = cb->clampToStartAndEndRegions(region);
+    RenderBoxRegionInfo* containingBlockInfo = cb->renderBoxRegionInfo(clampedContainingBlockRegion,
+        offsetFromLogicalTopOfFirstPage - logicalTop());
+    LayoutUnit containingBlockLogicalWidth = cb->logicalWidth();
+    LayoutUnit containingBlockLogicalWidthInRegion = containingBlockInfo ? containingBlockInfo->logicalWidth() : containingBlockLogicalWidth;
+    
+    LayoutUnit marginStartInRegion = marginStart();
+    LayoutUnit startMarginDelta = marginStartInRegion - oldMarginStart;
+    LayoutUnit logicalWidthInRegion = logicalWidth();
+    LayoutUnit logicalLeftInRegion = logicalLeft();
+    LayoutUnit widthDelta = logicalWidthInRegion - oldLogicalWidth;
+    LayoutUnit logicalLeftDelta = isPositioned() ? logicalLeftInRegion - oldLogicalLeft : startMarginDelta;
+    LayoutUnit logicalRightInRegion = containingBlockLogicalWidthInRegion - (logicalLeftInRegion + logicalWidthInRegion);
+    LayoutUnit oldLogicalRight = containingBlockLogicalWidth - (oldLogicalLeft + oldLogicalWidth);
+    LayoutUnit logicalRightDelta = isPositioned() ? logicalRightInRegion - oldLogicalRight : startMarginDelta;
+
+    // Set our values back.
+    mutableBox->setLogicalWidth(oldLogicalWidth);
+    mutableBox->setLogicalLeft(oldLogicalLeft);
+    mutableBox->setMarginStart(oldMarginStart);
+    mutableBox->setMarginEnd(oldMarginEnd);
+
+    LayoutUnit logicalLeftOffset = 0;
+    
+    if (!isPositioned() && avoidsFloats() && cb->containsFloats()) {
+        LayoutUnit startPositionDelta = cb->computeStartPositionDeltaForChildAvoidingFloats(this, marginStartInRegion, logicalWidthInRegion,
+            region, offsetFromLogicalTopOfFirstPage);
+        if (cb->style()->isLeftToRightDirection())
+            logicalLeftDelta += startPositionDelta;
+        else
+            logicalRightDelta += startPositionDelta;
+    }
+
+    if (cb->style()->isLeftToRightDirection())
+        logicalLeftOffset += logicalLeftDelta;
+    else
+        logicalLeftOffset -= (widthDelta + logicalRightDelta);
+    
+    LayoutUnit logicalRightOffset = logicalWidth() - (logicalLeftOffset + logicalWidthInRegion);
+    bool isShifted = (containingBlockInfo && containingBlockInfo->isShifted())
+            || (style()->isLeftToRightDirection() && logicalLeftOffset)
+            || (!style()->isLeftToRightDirection() && logicalRightOffset);
+
+    // FIXME: Although it's unlikely, these boxes can go outside our bounds, and so we will need to incorporate them into overflow.
+    if (cacheFlag == CacheRenderBoxRegionInfo)
+        return region->setRenderBoxRegionInfo(this, logicalLeftOffset, logicalWidthInRegion, isShifted);
+    return new RenderBoxRegionInfo(logicalLeftOffset, logicalWidthInRegion, isShifted);
+}
+
+void RenderBox::computeLogicalHeight()
+{
+    // Cell height is managed by the table and inline non-replaced elements do not support a height property.
+    if (isTableCell() || (isInline() && !isReplaced()))
+        return;
+
+    Length h;
+    if (isPositioned())
+        computePositionedLogicalHeight();
+    else {
+        RenderBlock* cb = containingBlock();
+        bool hasPerpendicularContainingBlock = cb->isHorizontalWritingMode() != isHorizontalWritingMode();
+    
+        if (!hasPerpendicularContainingBlock)
+            computeBlockDirectionMargins(cb);
+
+        // For tables, calculate margins only.
+        if (isTable()) {
+            if (hasPerpendicularContainingBlock)
+                computeInlineDirectionMargins(cb, containingBlockLogicalWidthForContent(), logicalHeight());
+            return;
+        }
+
+        // FIXME: Account for block-flow in flexible boxes.
+        // https://bugs.webkit.org/show_bug.cgi?id=46418
+        bool inHorizontalBox = parent()->isDeprecatedFlexibleBox() && parent()->style()->boxOrient() == HORIZONTAL;
+        bool stretching = parent()->style()->boxAlign() == BSTRETCH;
+        bool treatAsReplaced = shouldComputeSizeAsReplaced() && (!inHorizontalBox || !stretching);
+        bool checkMinMaxHeight = false;
+
+        // The parent box is flexing us, so it has increased or decreased our height.  We have to
+        // grab our cached flexible height.
+        // FIXME: Account for block-flow in flexible boxes.
+        // https://bugs.webkit.org/show_bug.cgi?id=46418
+        if (hasOverrideHeight() && parent()->isFlexibleBoxIncludingDeprecated())
+            h = Length(overrideHeight() - borderAndPaddingLogicalHeight(), Fixed);
+        else if (treatAsReplaced)
+            h = Length(computeReplacedLogicalHeight(), Fixed);
+        else {
+            h = style()->logicalHeight();
+            checkMinMaxHeight = true;
+        }
+
+        // Block children of horizontal flexible boxes fill the height of the box.
+        // FIXME: Account for block-flow in flexible boxes.
+        // https://bugs.webkit.org/show_bug.cgi?id=46418
+        if (h.isAuto() && parent()->isDeprecatedFlexibleBox() && parent()->style()->boxOrient() == HORIZONTAL
+                && parent()->isStretchingChildren()) {
+            h = Length(parentBox()->contentLogicalHeight() - marginBefore() - marginAfter() - borderAndPaddingLogicalHeight(), Fixed);
+            checkMinMaxHeight = false;
+        }
+
+        LayoutUnit heightResult;
+        if (checkMinMaxHeight) {
+            heightResult = computeLogicalHeightUsing(style()->logicalHeight());
+            // FIXME: Use < 0 or roughlyEquals when we move to float, see https://bugs.webkit.org/show_bug.cgi?id=66148
+            if (heightResult == -1)
+                heightResult = logicalHeight();
+            LayoutUnit minH = computeLogicalHeightUsing(style()->logicalMinHeight()); // Leave as -1 if unset.
+            LayoutUnit maxH = style()->logicalMaxHeight().isUndefined() ? heightResult : computeLogicalHeightUsing(style()->logicalMaxHeight());
+            if (maxH == -1)
+                maxH = heightResult;
+            heightResult = min(maxH, heightResult);
+            heightResult = max(minH, heightResult);
+        } else {
+            // The only times we don't check min/max height are when a fixed length has
+            // been given as an override.  Just use that.  The value has already been adjusted
+            // for box-sizing.
+            heightResult = h.value() + borderAndPaddingLogicalHeight();
+        }
+
+        setLogicalHeight(heightResult);
+        
+        if (hasPerpendicularContainingBlock)
+            computeInlineDirectionMargins(cb, containingBlockLogicalWidthForContent(), heightResult);
+    }
+
+    // WinIE quirk: The <html> block always fills the entire canvas in quirks mode.  The <body> always fills the
+    // <html> block in quirks mode.  Only apply this quirk if the block is normal flow and no height
+    // is specified. When we're printing, we also need this quirk if the body or root has a percentage 
+    // height since we don't set a height in RenderView when we're printing. So without this quirk, the 
+    // height has nothing to be a percentage of, and it ends up being 0. That is bad.
+    bool paginatedContentNeedsBaseHeight = document()->printing() && h.isPercent()
+        && (isRoot() || (isBody() && document()->documentElement()->renderer()->style()->logicalHeight().isPercent()));
+    if (stretchesToViewport() || paginatedContentNeedsBaseHeight) {
+        // FIXME: Finish accounting for block flow here.
+        // https://bugs.webkit.org/show_bug.cgi?id=46603
+        LayoutUnit margins = collapsedMarginBefore() + collapsedMarginAfter();
+        LayoutUnit visHeight;
+        if (document()->printing())
+            visHeight = static_cast<LayoutUnit>(view()->pageLogicalHeight());
+        else  {
+            if (isHorizontalWritingMode())
+                visHeight = view()->viewHeight();
+            else
+                visHeight = view()->viewWidth();
+        }
+        if (isRoot())
+            setLogicalHeight(max(logicalHeight(), visHeight - margins));
+        else {
+            LayoutUnit marginsBordersPadding = margins + parentBox()->marginBefore() + parentBox()->marginAfter() + parentBox()->borderAndPaddingLogicalHeight();
+            setLogicalHeight(max(logicalHeight(), visHeight - marginsBordersPadding));
+        }
+    }
+}
+
+LayoutUnit RenderBox::computeLogicalHeightUsing(const Length& h)
+{
+    LayoutUnit logicalHeight = -1;
+    if (!h.isAuto()) {
+        if (h.isFixed())
+            logicalHeight = h.value();
+        else if (h.isPercent())
+            logicalHeight = computePercentageLogicalHeight(h);
+        // FIXME: Use < 0 or roughlyEquals when we move to float, see https://bugs.webkit.org/show_bug.cgi?id=66148
+        if (logicalHeight != -1) {
+            logicalHeight = computeBorderBoxLogicalHeight(logicalHeight);
+            return logicalHeight;
+        }
+    }
+    return logicalHeight;
+}
+
+LayoutUnit RenderBox::computePercentageLogicalHeight(const Length& height)
+{
+    LayoutUnit result = -1;
+    
+    // In quirks mode, blocks with auto height are skipped, and we keep looking for an enclosing
+    // block that may have a specified height and then use it. In strict mode, this violates the
+    // specification, which states that percentage heights just revert to auto if the containing
+    // block has an auto height. We still skip anonymous containing blocks in both modes, though, and look
+    // only at explicit containers.
+    bool skippedAutoHeightContainingBlock = false;
+    RenderBlock* cb = containingBlock();
+    while (!cb->isRenderView() && !cb->isBody() && !cb->isTableCell() && !cb->isPositioned() && cb->style()->logicalHeight().isAuto()) {
+        if (!document()->inQuirksMode() && !cb->isAnonymousBlock())
+            break;
+        skippedAutoHeightContainingBlock = true;
+        cb = cb->containingBlock();
+        cb->addPercentHeightDescendant(this);
+    }
+
+    // A positioned element that specified both top/bottom or that specifies height should be treated as though it has a height
+    // explicitly specified that can be used for any percentage computations.
+    // FIXME: We can't just check top/bottom here.
+    // https://bugs.webkit.org/show_bug.cgi?id=46500
+    bool isPositionedWithSpecifiedHeight = cb->isPositioned() && (!cb->style()->logicalHeight().isAuto() || (!cb->style()->top().isAuto() && !cb->style()->bottom().isAuto()));
+
+    bool includeBorderPadding = isTable();
+
+    // Table cells violate what the CSS spec says to do with heights.  Basically we
+    // don't care if the cell specified a height or not.  We just always make ourselves
+    // be a percentage of the cell's current content height.
+    if (cb->isTableCell()) {
+        if (!skippedAutoHeightContainingBlock) {
+            if (!cb->hasOverrideHeight()) {
+                // Normally we would let the cell size intrinsically, but scrolling overflow has to be
+                // treated differently, since WinIE lets scrolled overflow regions shrink as needed.
+                // While we can't get all cases right, we can at least detect when the cell has a specified
+                // height or when the table has a specified height.  In these cases we want to initially have
+                // no size and allow the flexing of the table or the cell to its specified height to cause us
+                // to grow to fill the space.  This could end up being wrong in some cases, but it is
+                // preferable to the alternative (sizing intrinsically and making the row end up too big).
+                RenderTableCell* cell = toRenderTableCell(cb);
+                if (scrollsOverflowY() && (!cell->style()->logicalHeight().isAuto() || !cell->table()->style()->logicalHeight().isAuto()))
+                    return 0;
+                return -1;
+            }
+            result = cb->overrideHeight();
+            includeBorderPadding = true;
+        }
+    }
+    // Otherwise we only use our percentage height if our containing block had a specified
+    // height.
+    else if (cb->style()->logicalHeight().isFixed())
+        result = cb->computeContentBoxLogicalHeight(cb->style()->logicalHeight().value());
+    else if (cb->style()->logicalHeight().isPercent() && !isPositionedWithSpecifiedHeight) {
+        // We need to recur and compute the percentage height for our containing block.
+        result = cb->computePercentageLogicalHeight(cb->style()->logicalHeight());
+        // FIXME: Use < 0 or roughlyEquals when we move to float, see https://bugs.webkit.org/show_bug.cgi?id=66148
+        if (result != -1)
+            result = cb->computeContentBoxLogicalHeight(result);
+    } else if (cb->isRenderView() || (cb->isBody() && document()->inQuirksMode()) || isPositionedWithSpecifiedHeight) {
+        // Don't allow this to affect the block' height() member variable, since this
+        // can get called while the block is still laying out its kids.
+        LayoutUnit oldHeight = cb->logicalHeight();
+        cb->computeLogicalHeight();
+        result = cb->contentLogicalHeight();
+        cb->setLogicalHeight(oldHeight);
+    } else if (cb->isRoot() && isPositioned())
+        // Match the positioned objects behavior, which is that positioned objects will fill their viewport
+        // always.  Note we could only hit this case by recurring into computePercentageLogicalHeight on a positioned containing block.
+        result = cb->computeContentBoxLogicalHeight(cb->availableLogicalHeight());
+
+    // FIXME: Use < 0 or roughlyEquals when we move to float, see https://bugs.webkit.org/show_bug.cgi?id=66148
+    if (result != -1) {
+        result = height.calcValue(result);
+        if (includeBorderPadding) {
+            // It is necessary to use the border-box to match WinIE's broken
+            // box model.  This is essential for sizing inside
+            // table cells using percentage heights.
+            result -= borderAndPaddingLogicalHeight();
+            result = max<LayoutUnit>(0, result);
+        }
+    }
+    return result;
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalWidth(bool includeMaxWidth) const
+{
+    return computeReplacedLogicalWidthRespectingMinMaxWidth(computeReplacedLogicalWidthUsing(style()->logicalWidth()), includeMaxWidth);
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalWidthRespectingMinMaxWidth(LayoutUnit logicalWidth, bool includeMaxWidth) const
+{
+    LayoutUnit minLogicalWidth = computeReplacedLogicalWidthUsing(style()->logicalMinWidth());
+    LayoutUnit maxLogicalWidth = !includeMaxWidth || style()->logicalMaxWidth().isUndefined() ? logicalWidth : computeReplacedLogicalWidthUsing(style()->logicalMaxWidth());
+    return max(minLogicalWidth, min(logicalWidth, maxLogicalWidth));
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalWidthUsing(Length logicalWidth) const
+{
+    switch (logicalWidth.type()) {
+        case Fixed:
+            return computeContentBoxLogicalWidth(logicalWidth.value());
+        case Percent: {
+            // FIXME: containingBlockLogicalWidthForContent() is wrong if the replaced element's block-flow is perpendicular to the
+            // containing block's block-flow.
+            // https://bugs.webkit.org/show_bug.cgi?id=46496
+            const LayoutUnit cw = isPositioned() ? containingBlockLogicalWidthForPositioned(toRenderBoxModelObject(container())) : containingBlockLogicalWidthForContent();
+            if (cw > 0)
+                return computeContentBoxLogicalWidth(logicalWidth.calcMinValue(cw));
+        }
+        // fall through
+        default:
+            return intrinsicLogicalWidth();
+     }
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalHeight() const
+{
+    return computeReplacedLogicalHeightRespectingMinMaxHeight(computeReplacedLogicalHeightUsing(style()->logicalHeight()));
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalHeightRespectingMinMaxHeight(LayoutUnit logicalHeight) const
+{
+    LayoutUnit minLogicalHeight = computeReplacedLogicalHeightUsing(style()->logicalMinHeight());
+    LayoutUnit maxLogicalHeight = style()->logicalMaxHeight().isUndefined() ? logicalHeight : computeReplacedLogicalHeightUsing(style()->logicalMaxHeight());
+    return max(minLogicalHeight, min(logicalHeight, maxLogicalHeight));
+}
+
+LayoutUnit RenderBox::computeReplacedLogicalHeightUsing(Length logicalHeight) const
+{
+    switch (logicalHeight.type()) {
+        case Fixed:
+            return computeContentBoxLogicalHeight(logicalHeight.value());
+        case Percent:
+        {
+            RenderObject* cb = isPositioned() ? container() : containingBlock();
+            while (cb->isAnonymous()) {
+                cb = cb->containingBlock();
+                toRenderBlock(cb)->addPercentHeightDescendant(const_cast<RenderBox*>(this));
+            }
+
+            // FIXME: This calculation is not patched for block-flow yet.
+            // https://bugs.webkit.org/show_bug.cgi?id=46500
+            if (cb->isPositioned() && cb->style()->height().isAuto() && !(cb->style()->top().isAuto() || cb->style()->bottom().isAuto())) {
+                ASSERT(cb->isRenderBlock());
+                RenderBlock* block = toRenderBlock(cb);
+                LayoutUnit oldHeight = block->height();
+                block->computeLogicalHeight();
+                LayoutUnit newHeight = block->computeContentBoxLogicalHeight(block->contentHeight());
+                block->setHeight(oldHeight);
+                return computeContentBoxLogicalHeight(logicalHeight.calcValue(newHeight));
+            }
+            
+            // FIXME: availableLogicalHeight() is wrong if the replaced element's block-flow is perpendicular to the
+            // containing block's block-flow.
+            // https://bugs.webkit.org/show_bug.cgi?id=46496
+            LayoutUnit availableHeight;
+            if (isPositioned())
+                availableHeight = containingBlockLogicalHeightForPositioned(toRenderBoxModelObject(cb));
+            else {
+                availableHeight =  toRenderBox(cb)->availableLogicalHeight();
+                // It is necessary to use the border-box to match WinIE's broken
+                // box model.  This is essential for sizing inside
+                // table cells using percentage heights.
+                // FIXME: This needs to be made block-flow-aware.  If the cell and image are perpendicular block-flows, this isn't right.
+                // https://bugs.webkit.org/show_bug.cgi?id=46997
+                while (cb && !cb->isRenderView() && (cb->style()->logicalHeight().isAuto() || cb->style()->logicalHeight().isPercent())) {
+                    if (cb->isTableCell()) {
+                        // Don't let table cells squeeze percent-height replaced elements
+                        // <http://bugs.webkit.org/show_bug.cgi?id=15359>
+                        availableHeight = max(availableHeight, intrinsicLogicalHeight());
+                        return logicalHeight.calcValue(availableHeight - borderAndPaddingLogicalHeight());
+                    }
+                    cb = cb->containingBlock();
+                }
+            }
+            return computeContentBoxLogicalHeight(logicalHeight.calcValue(availableHeight));
+        }
+        default:
+            return intrinsicLogicalHeight();
+    }
+}
+
+LayoutUnit RenderBox::availableLogicalHeight() const
+{
+    return availableLogicalHeightUsing(style()->logicalHeight());
+}
+
+LayoutUnit RenderBox::availableLogicalHeightUsing(const Length& h) const
+{
+    if (h.isFixed())
+        return computeContentBoxLogicalHeight(h.value());
+
+    if (isRenderView())
+        return isHorizontalWritingMode() ? toRenderView(this)->frameView()->visibleHeight() : toRenderView(this)->frameView()->visibleWidth();
+
+    // We need to stop here, since we don't want to increase the height of the table
+    // artificially.  We're going to rely on this cell getting expanded to some new
+    // height, and then when we lay out again we'll use the calculation below.
+    if (isTableCell() && (h.isAuto() || h.isPercent()))
+        return overrideHeight() - borderAndPaddingLogicalWidth();
+
+    if (h.isPercent()) {
+        LayoutUnit availableHeight;
+        // https://bugs.webkit.org/show_bug.cgi?id=64046
+        // For absolutely positioned elements whose containing block is based on a block-level element,
+        // the percentage is calculated with respect to the height of the padding box of that element
+        if (isPositioned())
+            availableHeight = containingBlockLogicalHeightForPositioned(containingBlock());
+        else
+            availableHeight = containingBlock()->availableLogicalHeight();
+        return computeContentBoxLogicalHeight(h.calcValue(availableHeight));
+    }
+
+    // FIXME: We can't just check top/bottom here.
+    // https://bugs.webkit.org/show_bug.cgi?id=46500
+    if (isRenderBlock() && isPositioned() && style()->height().isAuto() && !(style()->top().isAuto() || style()->bottom().isAuto())) {
+        RenderBlock* block = const_cast<RenderBlock*>(toRenderBlock(this));
+        LayoutUnit oldHeight = block->logicalHeight();
+        block->computeLogicalHeight();
+        LayoutUnit newHeight = block->computeContentBoxLogicalHeight(block->contentLogicalHeight());
+        block->setLogicalHeight(oldHeight);
+        return computeContentBoxLogicalHeight(newHeight);
+    }
+
+    return containingBlock()->availableLogicalHeight();
+}
+
+void RenderBox::computeBlockDirectionMargins(RenderBlock* containingBlock)
+{
+    if (isTableCell()) {
+        // FIXME: Not right if we allow cells to have different directionality than the table.  If we do allow this, though,
+        // we may just do it with an extra anonymous block inside the cell.
+        setMarginBefore(0);
+        setMarginAfter(0);
+        return;
+    }
+
+    // Margins are calculated with respect to the logical width of
+    // the containing block (8.3)
+    LayoutUnit cw = containingBlockLogicalWidthForContent();
+
+    RenderStyle* containingBlockStyle = containingBlock->style();
+    containingBlock->setMarginBeforeForChild(this, style()->marginBeforeUsing(containingBlockStyle).calcMinValue(cw));
+    containingBlock->setMarginAfterForChild(this, style()->marginAfterUsing(containingBlockStyle).calcMinValue(cw));
+}
+
+LayoutUnit RenderBox::containingBlockLogicalWidthForPositioned(const RenderBoxModelObject* containingBlock, RenderRegion* region,
+    LayoutUnit offsetFromLogicalTopOfFirstPage, bool checkForPerpendicularWritingMode) const
+{
+    // Container for position:fixed is the frame.
+    Frame* frame = view() ? view()->frame(): 0;
+    FrameView* frameView = view() ? view()->frameView() : 0;
+    if (shouldLayoutFixedElementRelativeToFrame(frame, frameView))
+        return (view()->isHorizontalWritingMode() ? frameView->visibleWidth() : frameView->visibleHeight()) / frame->frameScaleFactor();
+
+    if (checkForPerpendicularWritingMode && containingBlock->isHorizontalWritingMode() != isHorizontalWritingMode())
+        return containingBlockLogicalHeightForPositioned(containingBlock, false);
+
+    if (containingBlock->isBox()) {
+        const RenderBlock* cb = toRenderBlock(containingBlock);
+        LayoutUnit result = cb->clientLogicalWidth();
+        if (inRenderFlowThread()) {
+            RenderBoxRegionInfo* boxInfo = 0;
+            if (!region) {
+                if (containingBlock->isRenderFlowThread() && !checkForPerpendicularWritingMode)
+                    return toRenderFlowThread(containingBlock)->contentLogicalWidthOfFirstRegion();
+                if (isWritingModeRoot()) {
+                    LayoutUnit cbPageOffset = offsetFromLogicalTopOfFirstPage - logicalTop();
+                    RenderRegion* cbRegion = cb->regionAtBlockOffset(cbPageOffset);
+                    cbRegion = cb->clampToStartAndEndRegions(cbRegion);
+                    boxInfo = cb->renderBoxRegionInfo(cbRegion, cbPageOffset);
+                }
+            } else if (region && enclosingRenderFlowThread()->isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode()) {
+                RenderRegion* containingBlockRegion = cb->clampToStartAndEndRegions(region);
+                boxInfo = cb->renderBoxRegionInfo(containingBlockRegion, offsetFromLogicalTopOfFirstPage - logicalTop());
+            }
+            if (boxInfo)
+                return max<LayoutUnit>(0, result - (cb->logicalWidth() - boxInfo->logicalWidth()));
+        }
+        return result;
+    }
+
+    ASSERT(containingBlock->isRenderInline() && containingBlock->isRelPositioned());
+
+    const RenderInline* flow = toRenderInline(containingBlock);
+    InlineFlowBox* first = flow->firstLineBox();
+    InlineFlowBox* last = flow->lastLineBox();
+
+    // If the containing block is empty, return a width of 0.
+    if (!first || !last)
+        return 0;
+
+    LayoutUnit fromLeft;
+    LayoutUnit fromRight;
+    if (containingBlock->style()->isLeftToRightDirection()) {
+        fromLeft = first->logicalLeft() + first->borderLogicalLeft();
+        fromRight = last->logicalLeft() + last->logicalWidth() - last->borderLogicalRight();
+    } else {
+        fromRight = first->logicalLeft() + first->logicalWidth() - first->borderLogicalRight();
+        fromLeft = last->logicalLeft() + last->borderLogicalLeft();
+    }
+
+    return max<LayoutUnit>(0, fromRight - fromLeft);
+}
+
+LayoutUnit RenderBox::containingBlockLogicalHeightForPositioned(const RenderBoxModelObject* containingBlock, bool checkForPerpendicularWritingMode) const
+{
+    Frame* frame = view() ? view()->frame(): 0;
+    FrameView* frameView = view() ? view()->frameView() : 0;
+    if (shouldLayoutFixedElementRelativeToFrame(frame, frameView))
+        return (view()->isHorizontalWritingMode() ? frameView->visibleHeight() : frameView->visibleWidth()) / frame->frameScaleFactor();
+
+    if (checkForPerpendicularWritingMode && containingBlock->isHorizontalWritingMode() != isHorizontalWritingMode())
+        return containingBlockLogicalWidthForPositioned(containingBlock, 0, 0, false);
+
+    if (containingBlock->isBox()) {
+        const RenderBlock* cb = toRenderBlock(containingBlock);
+        LayoutUnit result = cb->clientLogicalHeight();
+        if (inRenderFlowThread() && containingBlock->isRenderFlowThread() && enclosingRenderFlowThread()->isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode())
+            return toRenderFlowThread(containingBlock)->contentLogicalHeightOfFirstRegion();
+        return result;
+    }
+        
+    ASSERT(containingBlock->isRenderInline() && containingBlock->isRelPositioned());
+
+    const RenderInline* flow = toRenderInline(containingBlock);
+    InlineFlowBox* first = flow->firstLineBox();
+    InlineFlowBox* last = flow->lastLineBox();
+
+    // If the containing block is empty, return a height of 0.
+    if (!first || !last)
+        return 0;
+
+    LayoutUnit heightResult;
+    LayoutRect boundingBox = flow->linesBoundingBox();
+    if (containingBlock->isHorizontalWritingMode())
+        heightResult = boundingBox.height();
+    else
+        heightResult = boundingBox.width();
+    heightResult -= (containingBlock->borderBefore() + containingBlock->borderAfter());
+    return heightResult;
+}
+
+static void computeInlineStaticDistance(Length& logicalLeft, Length& logicalRight, const RenderBox* child, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalWidth, RenderRegion* region)
+{
+    if (!logicalLeft.isAuto() || !logicalRight.isAuto())
+        return;
+
+    // FIXME: The static distance computation has not been patched for mixed writing modes yet.
+    if (child->parent()->style()->direction() == LTR) {
+        LayoutUnit staticPosition = child->layer()->staticInlinePosition() - containerBlock->borderLogicalLeft();
+        for (RenderObject* curr = child->parent(); curr && curr != containerBlock; curr = curr->container()) {
+            if (curr->isBox()) {
+                staticPosition += toRenderBox(curr)->logicalLeft();
+                if (region && curr->isRenderBlock()) {
+                    const RenderBlock* cb = toRenderBlock(curr);
+                    region = cb->clampToStartAndEndRegions(region);
+                    RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(region, region->offsetFromLogicalTopOfFirstPage());
+                    if (boxInfo)
+                        staticPosition += boxInfo->logicalLeft();
+                }
+            }
+        }
+        logicalLeft.setValue(Fixed, staticPosition);
+    } else {
+        RenderBox* enclosingBox = child->parent()->enclosingBox();
+        LayoutUnit staticPosition = child->layer()->staticInlinePosition() + containerLogicalWidth + containerBlock->borderLogicalLeft();
+        for (RenderObject* curr = enclosingBox; curr; curr = curr->container()) {
+            if (curr->isBox()) {
+                if (curr != containerBlock)
+                    staticPosition -= toRenderBox(curr)->logicalLeft();
+                if (curr == enclosingBox)
+                    staticPosition -= enclosingBox->logicalWidth();
+                if (region && curr->isRenderBlock()) {
+                     const RenderBlock* cb = toRenderBlock(curr);
+                     region = cb->clampToStartAndEndRegions(region);
+                     RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(region, region->offsetFromLogicalTopOfFirstPage());
+                     if (boxInfo) {
+                        if (curr != containerBlock)
+                            staticPosition -= cb->logicalWidth() - (boxInfo->logicalLeft() + boxInfo->logicalWidth());
+                        if (curr == enclosingBox)
+                            staticPosition += enclosingBox->logicalWidth() - boxInfo->logicalWidth();
+                    }
+                }
+            }
+            if (curr == containerBlock)
+                break;
+        }
+        logicalRight.setValue(Fixed, staticPosition);
+    }
+}
+
+void RenderBox::computePositionedLogicalWidth(RenderRegion* region, LayoutUnit offsetFromLogicalTopOfFirstPage)
+{
+    if (isReplaced()) {
+        computePositionedLogicalWidthReplaced(); // FIXME: Patch for regions when we add replaced element support.
+        return;
+    }
+
+    // QUESTIONS
+    // FIXME 1: Should we still deal with these the cases of 'left' or 'right' having
+    // the type 'static' in determining whether to calculate the static distance?
+    // NOTE: 'static' is not a legal value for 'left' or 'right' as of CSS 2.1.
+
+    // FIXME 2: Can perhaps optimize out cases when max-width/min-width are greater
+    // than or less than the computed width().  Be careful of box-sizing and
+    // percentage issues.
+
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.3.7 "Absolutely positioned, non-replaced elements"
+    // <http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>
+    // (block-style-comments in this function and in computePositionedLogicalWidthUsing()
+    // correspond to text from the spec)
+
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing
+    // relative positioned inline.
+    const RenderBoxModelObject* containerBlock = toRenderBoxModelObject(container());
+    
+    const LayoutUnit containerLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock, region, offsetFromLogicalTopOfFirstPage);
+
+    // Use the container block's direction except when calculating the static distance
+    // This conforms with the reference results for abspos-replaced-width-margin-000.htm
+    // of the CSS 2.1 test suite
+    TextDirection containerDirection = containerBlock->style()->direction();
+
+    bool isHorizontal = isHorizontalWritingMode();
+    const LayoutUnit bordersPlusPadding = borderAndPaddingLogicalWidth();
+    const Length marginLogicalLeft = isHorizontal ? style()->marginLeft() : style()->marginTop();
+    const Length marginLogicalRight = isHorizontal ? style()->marginRight() : style()->marginBottom();
+    LayoutUnit& marginLogicalLeftAlias = isHorizontal ? m_marginLeft : m_marginTop;
+    LayoutUnit& marginLogicalRightAlias = isHorizontal ? m_marginRight : m_marginBottom;
+
+    Length logicalLeftLength = style()->logicalLeft();
+    Length logicalRightLength = style()->logicalRight();
+
+    /*---------------------------------------------------------------------------*\
+     * For the purposes of this section and the next, the term "static position"
+     * (of an element) refers, roughly, to the position an element would have had
+     * in the normal flow. More precisely:
+     *
+     * * The static position for 'left' is the distance from the left edge of the
+     *   containing block to the left margin edge of a hypothetical box that would
+     *   have been the first box of the element if its 'position' property had
+     *   been 'static' and 'float' had been 'none'. The value is negative if the
+     *   hypothetical box is to the left of the containing block.
+     * * The static position for 'right' is the distance from the right edge of the
+     *   containing block to the right margin edge of the same hypothetical box as
+     *   above. The value is positive if the hypothetical box is to the left of the
+     *   containing block's edge.
+     *
+     * But rather than actually calculating the dimensions of that hypothetical box,
+     * user agents are free to make a guess at its probable position.
+     *
+     * For the purposes of calculating the static position, the containing block of
+     * fixed positioned elements is the initial containing block instead of the
+     * viewport, and all scrollable boxes should be assumed to be scrolled to their
+     * origin.
+    \*---------------------------------------------------------------------------*/
+
+    // see FIXME 1
+    // Calculate the static distance if needed.
+    computeInlineStaticDistance(logicalLeftLength, logicalRightLength, this, containerBlock, containerLogicalWidth, region);
+    
+    // Calculate constraint equation values for 'width' case.
+    LayoutUnit logicalWidthResult;
+    LayoutUnit logicalLeftResult;
+    computePositionedLogicalWidthUsing(style()->logicalWidth(), containerBlock, containerDirection,
+                                       containerLogicalWidth, bordersPlusPadding,
+                                       logicalLeftLength, logicalRightLength, marginLogicalLeft, marginLogicalRight,
+                                       logicalWidthResult, marginLogicalLeftAlias, marginLogicalRightAlias, logicalLeftResult);
+    setLogicalWidth(logicalWidthResult);
+    setLogicalLeft(logicalLeftResult);
+
+    // Calculate constraint equation values for 'max-width' case.
+    if (!style()->logicalMaxWidth().isUndefined()) {
+        LayoutUnit maxLogicalWidth;
+        LayoutUnit maxMarginLogicalLeft;
+        LayoutUnit maxMarginLogicalRight;
+        LayoutUnit maxLogicalLeftPos;
+
+        computePositionedLogicalWidthUsing(style()->logicalMaxWidth(), containerBlock, containerDirection,
+                                           containerLogicalWidth, bordersPlusPadding,
+                                           logicalLeftLength, logicalRightLength, marginLogicalLeft, marginLogicalRight,
+                                           maxLogicalWidth, maxMarginLogicalLeft, maxMarginLogicalRight, maxLogicalLeftPos);
+
+        if (logicalWidth() > maxLogicalWidth) {
+            setLogicalWidth(maxLogicalWidth);
+            marginLogicalLeftAlias = maxMarginLogicalLeft;
+            marginLogicalRightAlias = maxMarginLogicalRight;
+            setLogicalLeft(maxLogicalLeftPos);
+        }
+    }
+
+    // Calculate constraint equation values for 'min-width' case.
+    if (!style()->logicalMinWidth().isZero()) {
+        LayoutUnit minLogicalWidth;
+        LayoutUnit minMarginLogicalLeft;
+        LayoutUnit minMarginLogicalRight;
+        LayoutUnit minLogicalLeftPos;
+
+        computePositionedLogicalWidthUsing(style()->logicalMinWidth(), containerBlock, containerDirection,
+                                           containerLogicalWidth, bordersPlusPadding,
+                                           logicalLeftLength, logicalRightLength, marginLogicalLeft, marginLogicalRight,
+                                           minLogicalWidth, minMarginLogicalLeft, minMarginLogicalRight, minLogicalLeftPos);
+
+        if (logicalWidth() < minLogicalWidth) {
+            setLogicalWidth(minLogicalWidth);
+            marginLogicalLeftAlias = minMarginLogicalLeft;
+            marginLogicalRightAlias = minMarginLogicalRight;
+            setLogicalLeft(minLogicalLeftPos);
+        }
+    }
+
+    if (stretchesToMinIntrinsicLogicalWidth() && logicalWidth() < minPreferredLogicalWidth() - bordersPlusPadding) {
+        computePositionedLogicalWidthUsing(Length(minPreferredLogicalWidth() - bordersPlusPadding, Fixed), containerBlock, containerDirection,
+                                           containerLogicalWidth, bordersPlusPadding,
+                                           logicalLeftLength, logicalRightLength, marginLogicalLeft, marginLogicalRight,
+                                           logicalWidthResult, marginLogicalLeftAlias, marginLogicalRightAlias, logicalLeftResult);
+        setLogicalWidth(logicalWidthResult);
+        setLogicalLeft(logicalLeftResult);
+    }
+
+    // Put logicalWidth() into correct form.
+    setLogicalWidth(logicalWidth() + bordersPlusPadding);
+    
+    // Adjust logicalLeft if we need to for the flipped version of our writing mode in regions.
+    if (inRenderFlowThread() && !region && isWritingModeRoot() && isHorizontalWritingMode() == containerBlock->isHorizontalWritingMode()) {
+        LayoutUnit logicalLeftPos = logicalLeft();
+        const RenderBlock* cb = toRenderBlock(containerBlock);
+        LayoutUnit cbPageOffset = offsetFromLogicalTopOfFirstPage - logicalTop();
+        RenderRegion* cbRegion = cb->regionAtBlockOffset(cbPageOffset);
+        cbRegion = cb->clampToStartAndEndRegions(cbRegion);
+        RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(cbRegion, cbPageOffset);
+        if (boxInfo) {
+            logicalLeftPos += boxInfo->logicalLeft();
+            setLogicalLeft(logicalLeftPos);
+        }
+    }
+}
+
+static void computeLogicalLeftPositionedOffset(LayoutUnit& logicalLeftPos, const RenderBox* child, LayoutUnit logicalWidthValue, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalWidth)
+{
+    // Deal with differing writing modes here.  Our offset needs to be in the containing block's coordinate space. If the containing block is flipped
+    // along this axis, then we need to flip the coordinate.  This can only happen if the containing block is both a flipped mode and perpendicular to us.
+    if (containerBlock->isHorizontalWritingMode() != child->isHorizontalWritingMode() && containerBlock->style()->isFlippedBlocksWritingMode()) {
+        logicalLeftPos = containerLogicalWidth - logicalWidthValue - logicalLeftPos;
+        logicalLeftPos += (child->isHorizontalWritingMode() ? containerBlock->borderRight() : containerBlock->borderBottom());
+    } else
+        logicalLeftPos += (child->isHorizontalWritingMode() ? containerBlock->borderLeft() : containerBlock->borderTop());
+}
+
+void RenderBox::computePositionedLogicalWidthUsing(Length logicalWidth, const RenderBoxModelObject* containerBlock, TextDirection containerDirection,
+                                                   LayoutUnit containerLogicalWidth, LayoutUnit bordersPlusPadding,
+                                                   Length logicalLeft, Length logicalRight, Length marginLogicalLeft, Length marginLogicalRight,
+                                                   LayoutUnit& logicalWidthValue, LayoutUnit& marginLogicalLeftValue, LayoutUnit& marginLogicalRightValue, LayoutUnit& logicalLeftPos)
+{
+    // 'left' and 'right' cannot both be 'auto' because one would of been
+    // converted to the static position already
+    ASSERT(!(logicalLeft.isAuto() && logicalRight.isAuto()));
+
+    LayoutUnit logicalLeftValue = 0;
+
+    bool logicalWidthIsAuto = logicalWidth.isIntrinsicOrAuto();
+    bool logicalLeftIsAuto = logicalLeft.isAuto();
+    bool logicalRightIsAuto = logicalRight.isAuto();
+
+    if (!logicalLeftIsAuto && !logicalWidthIsAuto && !logicalRightIsAuto) {
+        /*-----------------------------------------------------------------------*\
+         * If none of the three is 'auto': If both 'margin-left' and 'margin-
+         * right' are 'auto', solve the equation under the extra constraint that
+         * the two margins get equal values, unless this would make them negative,
+         * in which case when direction of the containing block is 'ltr' ('rtl'),
+         * set 'margin-left' ('margin-right') to zero and solve for 'margin-right'
+         * ('margin-left'). If one of 'margin-left' or 'margin-right' is 'auto',
+         * solve the equation for that value. If the values are over-constrained,
+         * ignore the value for 'left' (in case the 'direction' property of the
+         * containing block is 'rtl') or 'right' (in case 'direction' is 'ltr')
+         * and solve for that value.
+        \*-----------------------------------------------------------------------*/
+        // NOTE:  It is not necessary to solve for 'right' in the over constrained
+        // case because the value is not used for any further calculations.
+
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+        logicalWidthValue = computeContentBoxLogicalWidth(logicalWidth.calcValue(containerLogicalWidth));
+
+        const LayoutUnit availableSpace = containerLogicalWidth - (logicalLeftValue + logicalWidthValue + logicalRight.calcValue(containerLogicalWidth) + bordersPlusPadding);
+
+        // Margins are now the only unknown
+        if (marginLogicalLeft.isAuto() && marginLogicalRight.isAuto()) {
+            // Both margins auto, solve for equality
+            if (availableSpace >= 0) {
+                marginLogicalLeftValue = availableSpace / 2; // split the difference
+                marginLogicalRightValue = availableSpace - marginLogicalLeftValue; // account for odd valued differences
+            } else {
+                // Use the containing block's direction rather than the parent block's
+                // per CSS 2.1 reference test abspos-non-replaced-width-margin-000.
+                if (containerDirection == LTR) {
+                    marginLogicalLeftValue = 0;
+                    marginLogicalRightValue = availableSpace; // will be negative
+                } else {
+                    marginLogicalLeftValue = availableSpace; // will be negative
+                    marginLogicalRightValue = 0;
+                }
+            }
+        } else if (marginLogicalLeft.isAuto()) {
+            // Solve for left margin
+            marginLogicalRightValue = marginLogicalRight.calcValue(containerLogicalWidth);
+            marginLogicalLeftValue = availableSpace - marginLogicalRightValue;
+        } else if (marginLogicalRight.isAuto()) {
+            // Solve for right margin
+            marginLogicalLeftValue = marginLogicalLeft.calcValue(containerLogicalWidth);
+            marginLogicalRightValue = availableSpace - marginLogicalLeftValue;
+        } else {
+            // Over-constrained, solve for left if direction is RTL
+            marginLogicalLeftValue = marginLogicalLeft.calcValue(containerLogicalWidth);
+            marginLogicalRightValue = marginLogicalRight.calcValue(containerLogicalWidth);
+
+            // Use the containing block's direction rather than the parent block's
+            // per CSS 2.1 reference test abspos-non-replaced-width-margin-000.
+            if (containerDirection == RTL)
+                logicalLeftValue = (availableSpace + logicalLeftValue) - marginLogicalLeftValue - marginLogicalRightValue;
+        }
+    } else {
+        /*--------------------------------------------------------------------*\
+         * Otherwise, set 'auto' values for 'margin-left' and 'margin-right'
+         * to 0, and pick the one of the following six rules that applies.
+         *
+         * 1. 'left' and 'width' are 'auto' and 'right' is not 'auto', then the
+         *    width is shrink-to-fit. Then solve for 'left'
+         *
+         *              OMIT RULE 2 AS IT SHOULD NEVER BE HIT
+         * ------------------------------------------------------------------
+         * 2. 'left' and 'right' are 'auto' and 'width' is not 'auto', then if
+         *    the 'direction' property of the containing block is 'ltr' set
+         *    'left' to the static position, otherwise set 'right' to the
+         *    static position. Then solve for 'left' (if 'direction is 'rtl')
+         *    or 'right' (if 'direction' is 'ltr').
+         * ------------------------------------------------------------------
+         *
+         * 3. 'width' and 'right' are 'auto' and 'left' is not 'auto', then the
+         *    width is shrink-to-fit . Then solve for 'right'
+         * 4. 'left' is 'auto', 'width' and 'right' are not 'auto', then solve
+         *    for 'left'
+         * 5. 'width' is 'auto', 'left' and 'right' are not 'auto', then solve
+         *    for 'width'
+         * 6. 'right' is 'auto', 'left' and 'width' are not 'auto', then solve
+         *    for 'right'
+         *
+         * Calculation of the shrink-to-fit width is similar to calculating the
+         * width of a table cell using the automatic table layout algorithm.
+         * Roughly: calculate the preferred width by formatting the content
+         * without breaking lines other than where explicit line breaks occur,
+         * and also calculate the preferred minimum width, e.g., by trying all
+         * possible line breaks. CSS 2.1 does not define the exact algorithm.
+         * Thirdly, calculate the available width: this is found by solving
+         * for 'width' after setting 'left' (in case 1) or 'right' (in case 3)
+         * to 0.
+         *
+         * Then the shrink-to-fit width is:
+         * min(max(preferred minimum width, available width), preferred width).
+        \*--------------------------------------------------------------------*/
+        // NOTE: For rules 3 and 6 it is not necessary to solve for 'right'
+        // because the value is not used for any further calculations.
+
+        // Calculate margins, 'auto' margins are ignored.
+        marginLogicalLeftValue = marginLogicalLeft.calcMinValue(containerLogicalWidth);
+        marginLogicalRightValue = marginLogicalRight.calcMinValue(containerLogicalWidth);
+
+        const LayoutUnit availableSpace = containerLogicalWidth - (marginLogicalLeftValue + marginLogicalRightValue + bordersPlusPadding);
+
+        // FIXME: Is there a faster way to find the correct case?
+        // Use rule/case that applies.
+        if (logicalLeftIsAuto && logicalWidthIsAuto && !logicalRightIsAuto) {
+            // RULE 1: (use shrink-to-fit for width, and solve of left)
+            LayoutUnit logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+
+            // FIXME: would it be better to have shrink-to-fit in one step?
+            LayoutUnit preferredWidth = maxPreferredLogicalWidth() - bordersPlusPadding;
+            LayoutUnit preferredMinWidth = minPreferredLogicalWidth() - bordersPlusPadding;
+            LayoutUnit availableWidth = availableSpace - logicalRightValue;
+            logicalWidthValue = min(max(preferredMinWidth, availableWidth), preferredWidth);
+            logicalLeftValue = availableSpace - (logicalWidthValue + logicalRightValue);
+        } else if (!logicalLeftIsAuto && logicalWidthIsAuto && logicalRightIsAuto) {
+            // RULE 3: (use shrink-to-fit for width, and no need solve of right)
+            logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+
+            // FIXME: would it be better to have shrink-to-fit in one step?
+            LayoutUnit preferredWidth = maxPreferredLogicalWidth() - bordersPlusPadding;
+            LayoutUnit preferredMinWidth = minPreferredLogicalWidth() - bordersPlusPadding;
+            LayoutUnit availableWidth = availableSpace - logicalLeftValue;
+            logicalWidthValue = min(max(preferredMinWidth, availableWidth), preferredWidth);
+        } else if (logicalLeftIsAuto && !logicalWidthIsAuto && !logicalRightIsAuto) {
+            // RULE 4: (solve for left)
+            logicalWidthValue = computeContentBoxLogicalWidth(logicalWidth.calcValue(containerLogicalWidth));
+            logicalLeftValue = availableSpace - (logicalWidthValue + logicalRight.calcValue(containerLogicalWidth));
+        } else if (!logicalLeftIsAuto && logicalWidthIsAuto && !logicalRightIsAuto) {
+            // RULE 5: (solve for width)
+            logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+            logicalWidthValue = availableSpace - (logicalLeftValue + logicalRight.calcValue(containerLogicalWidth));
+        } else if (!logicalLeftIsAuto && !logicalWidthIsAuto && logicalRightIsAuto) {
+            // RULE 6: (no need solve for right)
+            logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+            logicalWidthValue = computeContentBoxLogicalWidth(logicalWidth.calcValue(containerLogicalWidth));
+        }
+    }
+
+    // Use computed values to calculate the horizontal position.
+
+    // FIXME: This hack is needed to calculate the  logical left position for a 'rtl' relatively
+    // positioned, inline because right now, it is using the logical left position
+    // of the first line box when really it should use the last line box.  When
+    // this is fixed elsewhere, this block should be removed.
+    if (containerBlock->isRenderInline() && !containerBlock->style()->isLeftToRightDirection()) {
+        const RenderInline* flow = toRenderInline(containerBlock);
+        InlineFlowBox* firstLine = flow->firstLineBox();
+        InlineFlowBox* lastLine = flow->lastLineBox();
+        if (firstLine && lastLine && firstLine != lastLine) {
+            logicalLeftPos = logicalLeftValue + marginLogicalLeftValue + lastLine->borderLogicalLeft() + (lastLine->logicalLeft() - firstLine->logicalLeft());
+            return;
+        }
+    }
+
+    logicalLeftPos = logicalLeftValue + marginLogicalLeftValue;
+    computeLogicalLeftPositionedOffset(logicalLeftPos, this, logicalWidthValue, containerBlock, containerLogicalWidth);
+}
+
+static void computeBlockStaticDistance(Length& logicalTop, Length& logicalBottom, const RenderBox* child, const RenderBoxModelObject* containerBlock)
+{
+    if (!logicalTop.isAuto() || !logicalBottom.isAuto())
+        return;
+    
+    // FIXME: The static distance computation has not been patched for mixed writing modes.
+    LayoutUnit staticLogicalTop = child->layer()->staticBlockPosition() - containerBlock->borderBefore();
+    for (RenderObject* curr = child->parent(); curr && curr != containerBlock; curr = curr->container()) {
+        if (curr->isBox() && !curr->isTableRow())
+            staticLogicalTop += toRenderBox(curr)->logicalTop();
+    }
+    logicalTop.setValue(Fixed, staticLogicalTop);
+}
+
+void RenderBox::computePositionedLogicalHeight()
+{
+    if (isReplaced()) {
+        computePositionedLogicalHeightReplaced();
+        return;
+    }
+
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.6.4 "Absolutely positioned, non-replaced elements"
+    // <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-non-replaced-height>
+    // (block-style-comments in this function and in computePositionedLogicalHeightUsing()
+    // correspond to text from the spec)
+
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing relpositioned inline.
+    const RenderBoxModelObject* containerBlock = toRenderBoxModelObject(container());
+
+    const LayoutUnit containerLogicalHeight = containingBlockLogicalHeightForPositioned(containerBlock);
+
+    bool isHorizontal = isHorizontalWritingMode();
+    bool isFlipped = style()->isFlippedBlocksWritingMode();
+    const LayoutUnit bordersPlusPadding = borderAndPaddingLogicalHeight();
+    const Length marginBefore = style()->marginBefore();
+    const Length marginAfter = style()->marginAfter();
+    LayoutUnit& marginBeforeAlias = isHorizontal ? (isFlipped ? m_marginBottom : m_marginTop) : (isFlipped ? m_marginRight: m_marginLeft);
+    LayoutUnit& marginAfterAlias = isHorizontal ? (isFlipped ? m_marginTop : m_marginBottom) : (isFlipped ? m_marginLeft: m_marginRight);
+
+    Length logicalTopLength = style()->logicalTop();
+    Length logicalBottomLength = style()->logicalBottom();
+        
+    /*---------------------------------------------------------------------------*\
+     * For the purposes of this section and the next, the term "static position"
+     * (of an element) refers, roughly, to the position an element would have had
+     * in the normal flow. More precisely, the static position for 'top' is the
+     * distance from the top edge of the containing block to the top margin edge
+     * of a hypothetical box that would have been the first box of the element if
+     * its 'position' property had been 'static' and 'float' had been 'none'. The
+     * value is negative if the hypothetical box is above the containing block.
+     *
+     * But rather than actually calculating the dimensions of that hypothetical
+     * box, user agents are free to make a guess at its probable position.
+     *
+     * For the purposes of calculating the static position, the containing block
+     * of fixed positioned elements is the initial containing block instead of
+     * the viewport.
+    \*---------------------------------------------------------------------------*/
+
+    // see FIXME 1
+    // Calculate the static distance if needed.
+    computeBlockStaticDistance(logicalTopLength, logicalBottomLength, this, containerBlock);
+
+    LayoutUnit logicalHeightResult; // Needed to compute overflow.
+    LayoutUnit logicalTopPos;
+
+    // Calculate constraint equation values for 'height' case.
+    computePositionedLogicalHeightUsing(style()->logicalHeight(), containerBlock, containerLogicalHeight, bordersPlusPadding,
+                                        logicalTopLength, logicalBottomLength, marginBefore, marginAfter,
+                                        logicalHeightResult, marginBeforeAlias, marginAfterAlias, logicalTopPos);
+    setLogicalTop(logicalTopPos);
+
+    // Avoid doing any work in the common case (where the values of min-height and max-height are their defaults).
+    // see FIXME 2
+
+    // Calculate constraint equation values for 'max-height' case.
+    if (!style()->logicalMaxHeight().isUndefined()) {
+        LayoutUnit maxLogicalHeight;
+        LayoutUnit maxMarginBefore;
+        LayoutUnit maxMarginAfter;
+        LayoutUnit maxLogicalTopPos;
+
+        computePositionedLogicalHeightUsing(style()->logicalMaxHeight(), containerBlock, containerLogicalHeight, bordersPlusPadding,
+                                            logicalTopLength, logicalBottomLength, marginBefore, marginAfter,
+                                            maxLogicalHeight, maxMarginBefore, maxMarginAfter, maxLogicalTopPos);
+
+        if (logicalHeightResult > maxLogicalHeight) {
+            logicalHeightResult = maxLogicalHeight;
+            marginBeforeAlias = maxMarginBefore;
+            marginAfterAlias = maxMarginAfter;
+            setLogicalTop(maxLogicalTopPos);
+        }
+    }
+
+    // Calculate constraint equation values for 'min-height' case.
+    if (!style()->logicalMinHeight().isZero()) {
+        LayoutUnit minLogicalHeight;
+        LayoutUnit minMarginBefore;
+        LayoutUnit minMarginAfter;
+        LayoutUnit minLogicalTopPos;
+
+        computePositionedLogicalHeightUsing(style()->logicalMinHeight(), containerBlock, containerLogicalHeight, bordersPlusPadding,
+                                            logicalTopLength, logicalBottomLength, marginBefore, marginAfter,
+                                            minLogicalHeight, minMarginBefore, minMarginAfter, minLogicalTopPos);
+
+        if (logicalHeightResult < minLogicalHeight) {
+            logicalHeightResult = minLogicalHeight;
+            marginBeforeAlias = minMarginBefore;
+            marginAfterAlias = minMarginAfter;
+            setLogicalTop(minLogicalTopPos);
+        }
+    }
+
+    // Set final height value.
+    setLogicalHeight(logicalHeightResult + bordersPlusPadding);
+    
+    // Adjust logicalTop if we need to for perpendicular writing modes in regions.
+    if (inRenderFlowThread() && isHorizontalWritingMode() != containerBlock->isHorizontalWritingMode()) {
+        LayoutUnit logicalTopPos = logicalTop();
+        const RenderBlock* cb = toRenderBlock(containerBlock);
+        LayoutUnit cbPageOffset = cb->offsetFromLogicalTopOfFirstPage() - logicalLeft();
+        RenderRegion* cbRegion = cb->regionAtBlockOffset(cbPageOffset);
+        cbRegion = cb->clampToStartAndEndRegions(cbRegion);
+        RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(cbRegion, cbPageOffset);
+        if (boxInfo) {
+            logicalTopPos += boxInfo->logicalLeft();
+            setLogicalTop(logicalTopPos);
+        }
+    }
+}
+
+static void computeLogicalTopPositionedOffset(LayoutUnit& logicalTopPos, const RenderBox* child, LayoutUnit logicalHeightValue, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalHeight)
+{
+    // Deal with differing writing modes here.  Our offset needs to be in the containing block's coordinate space. If the containing block is flipped
+    // along this axis, then we need to flip the coordinate.  This can only happen if the containing block is both a flipped mode and perpendicular to us.
+    if ((child->style()->isFlippedBlocksWritingMode() && child->isHorizontalWritingMode() != containerBlock->isHorizontalWritingMode())
+        || (child->style()->isFlippedBlocksWritingMode() != containerBlock->style()->isFlippedBlocksWritingMode() && child->isHorizontalWritingMode() == containerBlock->isHorizontalWritingMode()))
+        logicalTopPos = containerLogicalHeight - logicalHeightValue - logicalTopPos;
+
+    // Our offset is from the logical bottom edge in a flipped environment, e.g., right for vertical-rl and bottom for horizontal-bt.
+    if (containerBlock->style()->isFlippedBlocksWritingMode() && child->isHorizontalWritingMode() == containerBlock->isHorizontalWritingMode()) {
+        if (child->isHorizontalWritingMode())
+            logicalTopPos += containerBlock->borderBottom();
+        else
+            logicalTopPos += containerBlock->borderRight();
+    } else {
+        if (child->isHorizontalWritingMode())
+            logicalTopPos += containerBlock->borderTop();
+        else
+            logicalTopPos += containerBlock->borderLeft();
+    }
+}
+
+void RenderBox::computePositionedLogicalHeightUsing(Length logicalHeightLength, const RenderBoxModelObject* containerBlock,
+                                                    LayoutUnit containerLogicalHeight, LayoutUnit bordersPlusPadding,
+                                                    Length logicalTop, Length logicalBottom, Length marginBefore, Length marginAfter,
+                                                    LayoutUnit& logicalHeightValue, LayoutUnit& marginBeforeValue, LayoutUnit& marginAfterValue, LayoutUnit& logicalTopPos)
+{
+    // 'top' and 'bottom' cannot both be 'auto' because 'top would of been
+    // converted to the static position in computePositionedLogicalHeight()
+    ASSERT(!(logicalTop.isAuto() && logicalBottom.isAuto()));
+
+    LayoutUnit contentLogicalHeight = logicalHeight() - bordersPlusPadding;
+
+    LayoutUnit logicalTopValue = 0;
+
+    bool logicalHeightIsAuto = logicalHeightLength.isAuto();
+    bool logicalTopIsAuto = logicalTop.isAuto();
+    bool logicalBottomIsAuto = logicalBottom.isAuto();
+
+    // Height is never unsolved for tables.
+    if (isTable()) {
+        logicalHeightLength.setValue(Fixed, contentLogicalHeight);
+        logicalHeightIsAuto = false;
+    }
+
+    if (!logicalTopIsAuto && !logicalHeightIsAuto && !logicalBottomIsAuto) {
+        /*-----------------------------------------------------------------------*\
+         * If none of the three are 'auto': If both 'margin-top' and 'margin-
+         * bottom' are 'auto', solve the equation under the extra constraint that
+         * the two margins get equal values. If one of 'margin-top' or 'margin-
+         * bottom' is 'auto', solve the equation for that value. If the values
+         * are over-constrained, ignore the value for 'bottom' and solve for that
+         * value.
+        \*-----------------------------------------------------------------------*/
+        // NOTE:  It is not necessary to solve for 'bottom' in the over constrained
+        // case because the value is not used for any further calculations.
+
+        logicalHeightValue = computeContentBoxLogicalHeight(logicalHeightLength.calcValue(containerLogicalHeight));
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+
+        const LayoutUnit availableSpace = containerLogicalHeight - (logicalTopValue + logicalHeightValue + logicalBottom.calcValue(containerLogicalHeight) + bordersPlusPadding);
+
+        // Margins are now the only unknown
+        if (marginBefore.isAuto() && marginAfter.isAuto()) {
+            // Both margins auto, solve for equality
+            // NOTE: This may result in negative values.
+            marginBeforeValue = availableSpace / 2; // split the difference
+            marginAfterValue = availableSpace - marginBeforeValue; // account for odd valued differences
+        } else if (marginBefore.isAuto()) {
+            // Solve for top margin
+            marginAfterValue = marginAfter.calcValue(containerLogicalHeight);
+            marginBeforeValue = availableSpace - marginAfterValue;
+        } else if (marginAfter.isAuto()) {
+            // Solve for bottom margin
+            marginBeforeValue = marginBefore.calcValue(containerLogicalHeight);
+            marginAfterValue = availableSpace - marginBeforeValue;
+        } else {
+            // Over-constrained, (no need solve for bottom)
+            marginBeforeValue = marginBefore.calcValue(containerLogicalHeight);
+            marginAfterValue = marginAfter.calcValue(containerLogicalHeight);
+        }
+    } else {
+        /*--------------------------------------------------------------------*\
+         * Otherwise, set 'auto' values for 'margin-top' and 'margin-bottom'
+         * to 0, and pick the one of the following six rules that applies.
+         *
+         * 1. 'top' and 'height' are 'auto' and 'bottom' is not 'auto', then
+         *    the height is based on the content, and solve for 'top'.
+         *
+         *              OMIT RULE 2 AS IT SHOULD NEVER BE HIT
+         * ------------------------------------------------------------------
+         * 2. 'top' and 'bottom' are 'auto' and 'height' is not 'auto', then
+         *    set 'top' to the static position, and solve for 'bottom'.
+         * ------------------------------------------------------------------
+         *
+         * 3. 'height' and 'bottom' are 'auto' and 'top' is not 'auto', then
+         *    the height is based on the content, and solve for 'bottom'.
+         * 4. 'top' is 'auto', 'height' and 'bottom' are not 'auto', and
+         *    solve for 'top'.
+         * 5. 'height' is 'auto', 'top' and 'bottom' are not 'auto', and
+         *    solve for 'height'.
+         * 6. 'bottom' is 'auto', 'top' and 'height' are not 'auto', and
+         *    solve for 'bottom'.
+        \*--------------------------------------------------------------------*/
+        // NOTE: For rules 3 and 6 it is not necessary to solve for 'bottom'
+        // because the value is not used for any further calculations.
+
+        // Calculate margins, 'auto' margins are ignored.
+        marginBeforeValue = marginBefore.calcMinValue(containerLogicalHeight);
+        marginAfterValue = marginAfter.calcMinValue(containerLogicalHeight);
+
+        const LayoutUnit availableSpace = containerLogicalHeight - (marginBeforeValue + marginAfterValue + bordersPlusPadding);
+
+        // Use rule/case that applies.
+        if (logicalTopIsAuto && logicalHeightIsAuto && !logicalBottomIsAuto) {
+            // RULE 1: (height is content based, solve of top)
+            logicalHeightValue = contentLogicalHeight;
+            logicalTopValue = availableSpace - (logicalHeightValue + logicalBottom.calcValue(containerLogicalHeight));
+        } else if (!logicalTopIsAuto && logicalHeightIsAuto && logicalBottomIsAuto) {
+            // RULE 3: (height is content based, no need solve of bottom)
+            logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+            logicalHeightValue = contentLogicalHeight;
+        } else if (logicalTopIsAuto && !logicalHeightIsAuto && !logicalBottomIsAuto) {
+            // RULE 4: (solve of top)
+            logicalHeightValue = computeContentBoxLogicalHeight(logicalHeightLength.calcValue(containerLogicalHeight));
+            logicalTopValue = availableSpace - (logicalHeightValue + logicalBottom.calcValue(containerLogicalHeight));
+        } else if (!logicalTopIsAuto && logicalHeightIsAuto && !logicalBottomIsAuto) {
+            // RULE 5: (solve of height)
+            logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+            logicalHeightValue = max<LayoutUnit>(0, availableSpace - (logicalTopValue + logicalBottom.calcValue(containerLogicalHeight)));
+        } else if (!logicalTopIsAuto && !logicalHeightIsAuto && logicalBottomIsAuto) {
+            // RULE 6: (no need solve of bottom)
+            logicalHeightValue = computeContentBoxLogicalHeight(logicalHeightLength.calcValue(containerLogicalHeight));
+            logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+        }
+    }
+
+    // Use computed values to calculate the vertical position.
+    logicalTopPos = logicalTopValue + marginBeforeValue;
+    computeLogicalTopPositionedOffset(logicalTopPos, this, logicalHeightValue, containerBlock, containerLogicalHeight);
+}
+
+void RenderBox::computePositionedLogicalWidthReplaced()
+{
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.3.8 "Absolutely positioned, replaced elements"
+    // <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-replaced-width>
+    // (block-style-comments in this function correspond to text from the spec and
+    // the numbers correspond to numbers in spec)
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing
+    // relative positioned inline.
+    const RenderBoxModelObject* containerBlock = toRenderBoxModelObject(container());
+
+    const LayoutUnit containerLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock);
+
+    // To match WinIE, in quirks mode use the parent's 'direction' property
+    // instead of the the container block's.
+    TextDirection containerDirection = containerBlock->style()->direction();
+
+    // Variables to solve.
+    bool isHorizontal = isHorizontalWritingMode();
+    Length logicalLeft = style()->logicalLeft();
+    Length logicalRight = style()->logicalRight();
+    Length marginLogicalLeft = isHorizontal ? style()->marginLeft() : style()->marginTop();
+    Length marginLogicalRight = isHorizontal ? style()->marginRight() : style()->marginBottom();
+    LayoutUnit& marginLogicalLeftAlias = isHorizontal ? m_marginLeft : m_marginTop;
+    LayoutUnit& marginLogicalRightAlias = isHorizontal ? m_marginRight : m_marginBottom;
+
+    /*-----------------------------------------------------------------------*\
+     * 1. The used value of 'width' is determined as for inline replaced
+     *    elements.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: This value of width is FINAL in that the min/max width calculations
+    // are dealt with in computeReplacedWidth().  This means that the steps to produce
+    // correct max/min in the non-replaced version, are not necessary.
+    setLogicalWidth(computeReplacedLogicalWidth() + borderAndPaddingLogicalWidth());
+
+    const LayoutUnit availableSpace = containerLogicalWidth - logicalWidth();
+
+    /*-----------------------------------------------------------------------*\
+     * 2. If both 'left' and 'right' have the value 'auto', then if 'direction'
+     *    of the containing block is 'ltr', set 'left' to the static position;
+     *    else if 'direction' is 'rtl', set 'right' to the static position.
+    \*-----------------------------------------------------------------------*/
+    // see FIXME 1
+    computeInlineStaticDistance(logicalLeft, logicalRight, this, containerBlock, containerLogicalWidth, 0); // FIXME: Pass the region.
+
+    /*-----------------------------------------------------------------------*\
+     * 3. If 'left' or 'right' are 'auto', replace any 'auto' on 'margin-left'
+     *    or 'margin-right' with '0'.
+    \*-----------------------------------------------------------------------*/
+    if (logicalLeft.isAuto() || logicalRight.isAuto()) {
+        if (marginLogicalLeft.isAuto())
+            marginLogicalLeft.setValue(Fixed, 0);
+        if (marginLogicalRight.isAuto())
+            marginLogicalRight.setValue(Fixed, 0);
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 4. If at this point both 'margin-left' and 'margin-right' are still
+     *    'auto', solve the equation under the extra constraint that the two
+     *    margins must get equal values, unless this would make them negative,
+     *    in which case when the direction of the containing block is 'ltr'
+     *    ('rtl'), set 'margin-left' ('margin-right') to zero and solve for
+     *    'margin-right' ('margin-left').
+    \*-----------------------------------------------------------------------*/
+    LayoutUnit logicalLeftValue = 0;
+    LayoutUnit logicalRightValue = 0;
+
+    if (marginLogicalLeft.isAuto() && marginLogicalRight.isAuto()) {
+        // 'left' and 'right' cannot be 'auto' due to step 3
+        ASSERT(!(logicalLeft.isAuto() && logicalRight.isAuto()));
+
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+        logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+
+        LayoutUnit difference = availableSpace - (logicalLeftValue + logicalRightValue);
+        if (difference > 0) {
+            marginLogicalLeftAlias = difference / 2; // split the difference
+            marginLogicalRightAlias = difference - marginLogicalLeftAlias; // account for odd valued differences
+        } else {
+            // Use the containing block's direction rather than the parent block's
+            // per CSS 2.1 reference test abspos-replaced-width-margin-000.
+            if (containerDirection == LTR) {
+                marginLogicalLeftAlias = 0;
+                marginLogicalRightAlias = difference; // will be negative
+            } else {
+                marginLogicalLeftAlias = difference; // will be negative
+                marginLogicalRightAlias = 0;
+            }
+        }
+
+    /*-----------------------------------------------------------------------*\
+     * 5. If at this point there is an 'auto' left, solve the equation for
+     *    that value.
+    \*-----------------------------------------------------------------------*/
+    } else if (logicalLeft.isAuto()) {
+        marginLogicalLeftAlias = marginLogicalLeft.calcValue(containerLogicalWidth);
+        marginLogicalRightAlias = marginLogicalRight.calcValue(containerLogicalWidth);
+        logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+
+        // Solve for 'left'
+        logicalLeftValue = availableSpace - (logicalRightValue + marginLogicalLeftAlias + marginLogicalRightAlias);
+    } else if (logicalRight.isAuto()) {
+        marginLogicalLeftAlias = marginLogicalLeft.calcValue(containerLogicalWidth);
+        marginLogicalRightAlias = marginLogicalRight.calcValue(containerLogicalWidth);
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+
+        // Solve for 'right'
+        logicalRightValue = availableSpace - (logicalLeftValue + marginLogicalLeftAlias + marginLogicalRightAlias);
+    } else if (marginLogicalLeft.isAuto()) {
+        marginLogicalRightAlias = marginLogicalRight.calcValue(containerLogicalWidth);
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+        logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+
+        // Solve for 'margin-left'
+        marginLogicalLeftAlias = availableSpace - (logicalLeftValue + logicalRightValue + marginLogicalRightAlias);
+    } else if (marginLogicalRight.isAuto()) {
+        marginLogicalLeftAlias = marginLogicalLeft.calcValue(containerLogicalWidth);
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+        logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+
+        // Solve for 'margin-right'
+        marginLogicalRightAlias = availableSpace - (logicalLeftValue + logicalRightValue + marginLogicalLeftAlias);
+    } else {
+        // Nothing is 'auto', just calculate the values.
+        marginLogicalLeftAlias = marginLogicalLeft.calcValue(containerLogicalWidth);
+        marginLogicalRightAlias = marginLogicalRight.calcValue(containerLogicalWidth);
+        logicalRightValue = logicalRight.calcValue(containerLogicalWidth);
+        logicalLeftValue = logicalLeft.calcValue(containerLogicalWidth);
+        // If the containing block is right-to-left, then push the left position as far to the right as possible
+        if (containerDirection == RTL) {
+            int totalLogicalWidth = logicalWidth() + logicalLeftValue + logicalRightValue +  marginLogicalLeftAlias + marginLogicalRightAlias;
+            logicalLeftValue = containerLogicalWidth - (totalLogicalWidth - logicalLeftValue);
+        }
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 6. If at this point the values are over-constrained, ignore the value
+     *    for either 'left' (in case the 'direction' property of the
+     *    containing block is 'rtl') or 'right' (in case 'direction' is
+     *    'ltr') and solve for that value.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: Constraints imposed by the width of the containing block and its content have already been accounted for above.
+
+    // FIXME: Deal with differing writing modes here.  Our offset needs to be in the containing block's coordinate space, so that
+    // can make the result here rather complicated to compute.
+
+    // Use computed values to calculate the horizontal position.
+
+    // FIXME: This hack is needed to calculate the logical left position for a 'rtl' relatively
+    // positioned, inline containing block because right now, it is using the logical left position
+    // of the first line box when really it should use the last line box.  When
+    // this is fixed elsewhere, this block should be removed.
+    if (containerBlock->isRenderInline() && !containerBlock->style()->isLeftToRightDirection()) {
+        const RenderInline* flow = toRenderInline(containerBlock);
+        InlineFlowBox* firstLine = flow->firstLineBox();
+        InlineFlowBox* lastLine = flow->lastLineBox();
+        if (firstLine && lastLine && firstLine != lastLine) {
+            setLogicalLeft(logicalLeftValue + marginLogicalLeftAlias + lastLine->borderLogicalLeft() + (lastLine->logicalLeft() - firstLine->logicalLeft()));
+            return;
+        }
+    }
+
+    LayoutUnit logicalLeftPos = logicalLeftValue + marginLogicalLeftAlias;
+    computeLogicalLeftPositionedOffset(logicalLeftPos, this, logicalWidth(), containerBlock, containerLogicalWidth);
+    setLogicalLeft(logicalLeftPos);
+}
+
+void RenderBox::computePositionedLogicalHeightReplaced()
+{
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.6.5 "Absolutely positioned, replaced elements"
+    // <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-replaced-height>
+    // (block-style-comments in this function correspond to text from the spec and
+    // the numbers correspond to numbers in spec)
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing relpositioned inline.
+    const RenderBoxModelObject* containerBlock = toRenderBoxModelObject(container());
+
+    const LayoutUnit containerLogicalHeight = containingBlockLogicalHeightForPositioned(containerBlock);
+
+    // Variables to solve.
+    bool isHorizontal = isHorizontalWritingMode();
+    bool isFlipped = style()->isFlippedBlocksWritingMode();
+    Length marginBefore = style()->marginBefore();
+    Length marginAfter = style()->marginAfter();
+    LayoutUnit& marginBeforeAlias = isHorizontal ? (isFlipped ? m_marginBottom : m_marginTop) : (isFlipped ? m_marginRight: m_marginLeft);
+    LayoutUnit& marginAfterAlias = isHorizontal ? (isFlipped ? m_marginTop : m_marginBottom) : (isFlipped ? m_marginLeft: m_marginRight);
+
+    Length logicalTop = style()->logicalTop();
+    Length logicalBottom = style()->logicalBottom();
+
+    /*-----------------------------------------------------------------------*\
+     * 1. The used value of 'height' is determined as for inline replaced
+     *    elements.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: This value of height is FINAL in that the min/max height calculations
+    // are dealt with in computeReplacedHeight().  This means that the steps to produce
+    // correct max/min in the non-replaced version, are not necessary.
+    setLogicalHeight(computeReplacedLogicalHeight() + borderAndPaddingLogicalHeight());
+    const LayoutUnit availableSpace = containerLogicalHeight - logicalHeight();
+
+    /*-----------------------------------------------------------------------*\
+     * 2. If both 'top' and 'bottom' have the value 'auto', replace 'top'
+     *    with the element's static position.
+    \*-----------------------------------------------------------------------*/
+    // see FIXME 1
+    computeBlockStaticDistance(logicalTop, logicalBottom, this, containerBlock);
+
+    /*-----------------------------------------------------------------------*\
+     * 3. If 'bottom' is 'auto', replace any 'auto' on 'margin-top' or
+     *    'margin-bottom' with '0'.
+    \*-----------------------------------------------------------------------*/
+    // FIXME: The spec. says that this step should only be taken when bottom is
+    // auto, but if only top is auto, this makes step 4 impossible.
+    if (logicalTop.isAuto() || logicalBottom.isAuto()) {
+        if (marginBefore.isAuto())
+            marginBefore.setValue(Fixed, 0);
+        if (marginAfter.isAuto())
+            marginAfter.setValue(Fixed, 0);
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 4. If at this point both 'margin-top' and 'margin-bottom' are still
+     *    'auto', solve the equation under the extra constraint that the two
+     *    margins must get equal values.
+    \*-----------------------------------------------------------------------*/
+    LayoutUnit logicalTopValue = 0;
+    LayoutUnit logicalBottomValue = 0;
+
+    if (marginBefore.isAuto() && marginAfter.isAuto()) {
+        // 'top' and 'bottom' cannot be 'auto' due to step 2 and 3 combined.
+        ASSERT(!(logicalTop.isAuto() || logicalBottom.isAuto()));
+
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+        logicalBottomValue = logicalBottom.calcValue(containerLogicalHeight);
+
+        LayoutUnit difference = availableSpace - (logicalTopValue + logicalBottomValue);
+        // NOTE: This may result in negative values.
+        marginBeforeAlias =  difference / 2; // split the difference
+        marginAfterAlias = difference - marginBeforeAlias; // account for odd valued differences
+
+    /*-----------------------------------------------------------------------*\
+     * 5. If at this point there is only one 'auto' left, solve the equation
+     *    for that value.
+    \*-----------------------------------------------------------------------*/
+    } else if (logicalTop.isAuto()) {
+        marginBeforeAlias = marginBefore.calcValue(containerLogicalHeight);
+        marginAfterAlias = marginAfter.calcValue(containerLogicalHeight);
+        logicalBottomValue = logicalBottom.calcValue(containerLogicalHeight);
+
+        // Solve for 'top'
+        logicalTopValue = availableSpace - (logicalBottomValue + marginBeforeAlias + marginAfterAlias);
+    } else if (logicalBottom.isAuto()) {
+        marginBeforeAlias = marginBefore.calcValue(containerLogicalHeight);
+        marginAfterAlias = marginAfter.calcValue(containerLogicalHeight);
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+
+        // Solve for 'bottom'
+        // NOTE: It is not necessary to solve for 'bottom' because we don't ever
+        // use the value.
+    } else if (marginBefore.isAuto()) {
+        marginAfterAlias = marginAfter.calcValue(containerLogicalHeight);
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+        logicalBottomValue = logicalBottom.calcValue(containerLogicalHeight);
+
+        // Solve for 'margin-top'
+        marginBeforeAlias = availableSpace - (logicalTopValue + logicalBottomValue + marginAfterAlias);
+    } else if (marginAfter.isAuto()) {
+        marginBeforeAlias = marginBefore.calcValue(containerLogicalHeight);
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+        logicalBottomValue = logicalBottom.calcValue(containerLogicalHeight);
+
+        // Solve for 'margin-bottom'
+        marginAfterAlias = availableSpace - (logicalTopValue + logicalBottomValue + marginBeforeAlias);
+    } else {
+        // Nothing is 'auto', just calculate the values.
+        marginBeforeAlias = marginBefore.calcValue(containerLogicalHeight);
+        marginAfterAlias = marginAfter.calcValue(containerLogicalHeight);
+        logicalTopValue = logicalTop.calcValue(containerLogicalHeight);
+        // NOTE: It is not necessary to solve for 'bottom' because we don't ever
+        // use the value.
+     }
+
+    /*-----------------------------------------------------------------------*\
+     * 6. If at this point the values are over-constrained, ignore the value
+     *    for 'bottom' and solve for that value.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: It is not necessary to do this step because we don't end up using
+    // the value of 'bottom' regardless of whether the values are over-constrained
+    // or not.
+
+    // Use computed values to calculate the vertical position.
+    LayoutUnit logicalTopPos = logicalTopValue + marginBeforeAlias;
+    computeLogicalTopPositionedOffset(logicalTopPos, this, logicalHeight(), containerBlock, containerLogicalHeight);
+    setLogicalTop(logicalTopPos);
+}
+
+LayoutRect RenderBox::localCaretRect(InlineBox* box, int caretOffset, LayoutUnit* extraWidthToEndOfLine)
+{
+    // VisiblePositions at offsets inside containers either a) refer to the positions before/after
+    // those containers (tables and select elements) or b) refer to the position inside an empty block.
+    // They never refer to children.
+    // FIXME: Paint the carets inside empty blocks differently than the carets before/after elements.
+
+    // FIXME: What about border and padding?
+    LayoutRect rect(x(), y(), caretWidth, height());
+    bool ltr = box ? box->isLeftToRightDirection() : style()->isLeftToRightDirection();
+
+    if ((!caretOffset) ^ ltr)
+        rect.move(LayoutSize(width() - caretWidth, 0));
+
+    if (box) {
+        RootInlineBox* rootBox = box->root();
+        LayoutUnit top = rootBox->lineTop();
+        rect.setY(top);
+        rect.setHeight(rootBox->lineBottom() - top);
+    }
+
+    // If height of box is smaller than font height, use the latter one,
+    // otherwise the caret might become invisible.
+    //
+    // Also, if the box is not a replaced element, always use the font height.
+    // This prevents the "big caret" bug described in:
+    // <rdar://problem/3777804> Deleting all content in a document can result in giant tall-as-window insertion point
+    //
+    // FIXME: ignoring :first-line, missing good reason to take care of
+    LayoutUnit fontHeight = style()->fontMetrics().height();
+    if (fontHeight > rect.height() || (!isReplaced() && !isTable()))
+        rect.setHeight(fontHeight);
+
+    if (extraWidthToEndOfLine)
+        *extraWidthToEndOfLine = x() + width() - rect.maxX();
+
+    // Move to local coords
+    rect.moveBy(-location());
+    return rect;
+}
+
+VisiblePosition RenderBox::positionForPoint(const LayoutPoint& point)
+{
+    // no children...return this render object's element, if there is one, and offset 0
+    if (!firstChild())
+        return createVisiblePosition(node() ? firstPositionInOrBeforeNode(node()) : Position());
+
+    if (isTable() && node()) {
+        LayoutUnit right = contentWidth() + borderAndPaddingWidth();
+        LayoutUnit bottom = contentHeight() + borderAndPaddingHeight();
+        
+        if (point.x() < 0 || point.x() > right || point.y() < 0 || point.y() > bottom) {
+            if (point.x() <= right / 2)
+                return createVisiblePosition(firstPositionInOrBeforeNode(node()));
+            return createVisiblePosition(lastPositionInOrAfterNode(node()));
+        }
+    }
+
+    // Pass off to the closest child.
+    LayoutUnit minDist = numeric_limits<LayoutUnit>::max();
+    RenderBox* closestRenderer = 0;
+    LayoutPoint adjustedPoint = point;
+    if (isTableRow())
+        adjustedPoint.moveBy(location());
+
+    for (RenderObject* renderObject = firstChild(); renderObject; renderObject = renderObject->nextSibling()) {
+        if ((!renderObject->firstChild() && !renderObject->isInline() && !renderObject->isBlockFlow() )
+            || renderObject->style()->visibility() != VISIBLE)
+            continue;
+        
+        if (!renderObject->isBox())
+            continue;
+        
+        RenderBox* renderer = toRenderBox(renderObject);
+
+        LayoutUnit top = renderer->borderTop() + renderer->paddingTop() + (isTableRow() ? 0 : renderer->y());
+        LayoutUnit bottom = top + renderer->contentHeight();
+        LayoutUnit left = renderer->borderLeft() + renderer->paddingLeft() + (isTableRow() ? 0 : renderer->x());
+        LayoutUnit right = left + renderer->contentWidth();
+        
+        if (point.x() <= right && point.x() >= left && point.y() <= top && point.y() >= bottom) {
+            if (renderer->isTableRow())
+                return renderer->positionForPoint(point + adjustedPoint - renderer->locationOffset());
+            return renderer->positionForPoint(point - renderer->locationOffset());
+        }
+
+        // Find the distance from (x, y) to the box.  Split the space around the box into 8 pieces
+        // and use a different compare depending on which piece (x, y) is in.
+        LayoutPoint cmp;
+        if (point.x() > right) {
+            if (point.y() < top)
+                cmp = LayoutPoint(right, top);
+            else if (point.y() > bottom)
+                cmp = LayoutPoint(right, bottom);
+            else
+                cmp = LayoutPoint(right, point.y());
+        } else if (point.x() < left) {
+            if (point.y() < top)
+                cmp = LayoutPoint(left, top);
+            else if (point.y() > bottom)
+                cmp = LayoutPoint(left, bottom);
+            else
+                cmp = LayoutPoint(left, point.y());
+        } else {
+            if (point.y() < top)
+                cmp = LayoutPoint(point.x(), top);
+            else
+                cmp = LayoutPoint(point.x(), bottom);
+        }
+
+        LayoutSize difference = cmp - point;
+
+        LayoutUnit dist = difference.width() * difference.width() + difference.height() * difference.height();
+        if (dist < minDist) {
+            closestRenderer = renderer;
+            minDist = dist;
+        }
+    }
+    
+    if (closestRenderer)
+        return closestRenderer->positionForPoint(adjustedPoint - closestRenderer->locationOffset());
+    
+    return createVisiblePosition(firstPositionInOrBeforeNode(node()));
+}
+
+bool RenderBox::shrinkToAvoidFloats() const
+{
+    // Floating objects don't shrink.  Objects that don't avoid floats don't shrink.  Marquees don't shrink.
+    if ((isInline() && !isHTMLMarquee()) || !avoidsFloats() || isFloating())
+        return false;
+
+    // All auto-width objects that avoid floats should always use lineWidth.
+    return style()->width().isAuto(); 
+}
+
+bool RenderBox::avoidsFloats() const
+{
+    return isReplaced() || hasOverflowClip() || isHR() || isLegend() || isWritingModeRoot() || isDeprecatedFlexItem();
+}
+
+void RenderBox::addVisualEffectOverflow()
+{
+    if (!style()->boxShadow() && !style()->hasBorderImageOutsets() && !style()->hasFilterOutsets())
+        return;
+
+    bool isFlipped = style()->isFlippedBlocksWritingMode();
+    bool isHorizontal = isHorizontalWritingMode();
+    
+    LayoutRect borderBox = borderBoxRect();
+    LayoutUnit overflowMinX = borderBox.x();
+    LayoutUnit overflowMaxX = borderBox.maxX();
+    LayoutUnit overflowMinY = borderBox.y();
+    LayoutUnit overflowMaxY = borderBox.maxY();
+    
+    // Compute box-shadow overflow first.
+    if (style()->boxShadow()) {
+        LayoutUnit shadowLeft;
+        LayoutUnit shadowRight;
+        LayoutUnit shadowTop;
+        LayoutUnit shadowBottom;
+        style()->getBoxShadowExtent(shadowTop, shadowRight, shadowBottom, shadowLeft);
+
+        // In flipped blocks writing modes such as vertical-rl, the physical right shadow value is actually at the lower x-coordinate.
+        overflowMinX = borderBox.x() + ((!isFlipped || isHorizontal) ? shadowLeft : -shadowRight);
+        overflowMaxX = borderBox.maxX() + ((!isFlipped || isHorizontal) ? shadowRight : -shadowLeft);
+        overflowMinY = borderBox.y() + ((!isFlipped || !isHorizontal) ? shadowTop : -shadowBottom);
+        overflowMaxY = borderBox.maxY() + ((!isFlipped || !isHorizontal) ? shadowBottom : -shadowTop);
+    }
+
+    // Now compute border-image-outset overflow.
+    if (style()->hasBorderImageOutsets()) {
+        LayoutUnit borderOutsetLeft;
+        LayoutUnit borderOutsetRight;
+        LayoutUnit borderOutsetTop;
+        LayoutUnit borderOutsetBottom;
+        style()->getBorderImageOutsets(borderOutsetTop, borderOutsetRight, borderOutsetBottom, borderOutsetLeft);
+        
+        // In flipped blocks writing modes, the physical sides are inverted. For example in vertical-rl, the right
+        // border is at the lower x coordinate value.
+        overflowMinX = min(overflowMinX, borderBox.x() - ((!isFlipped || isHorizontal) ? borderOutsetLeft : borderOutsetRight));
+        overflowMaxX = max(overflowMaxX, borderBox.maxX() + ((!isFlipped || isHorizontal) ? borderOutsetRight : borderOutsetLeft));
+        overflowMinY = min(overflowMinY, borderBox.y() - ((!isFlipped || !isHorizontal) ? borderOutsetTop : borderOutsetBottom));
+        overflowMaxY = max(overflowMaxY, borderBox.maxY() + ((!isFlipped || !isHorizontal) ? borderOutsetBottom : borderOutsetTop));
+    }
+
+#if ENABLE(CSS_FILTERS)
+    // Compute any filter outset overflow.
+    if (style()->hasFilterOutsets()) {
+        LayoutUnit filterOutsetLeft;
+        LayoutUnit filterOutsetRight;
+        LayoutUnit filterOutsetTop;
+        LayoutUnit filterOutsetBottom;
+        style()->getFilterOutsets(filterOutsetTop, filterOutsetRight, filterOutsetBottom, filterOutsetLeft);
+        
+        overflowMinX = min(overflowMinX, borderBox.x() - filterOutsetLeft);
+        overflowMaxX = max(overflowMaxX, borderBox.maxX() + filterOutsetRight);
+        overflowMinY = min(overflowMinY, borderBox.y() - filterOutsetTop);
+        overflowMaxY = max(overflowMaxY, borderBox.maxY() + filterOutsetBottom);
+    }
+#endif
+    // Add in the final overflow with shadows and outsets combined.
+    addVisualOverflow(LayoutRect(overflowMinX, overflowMinY, overflowMaxX - overflowMinX, overflowMaxY - overflowMinY));
+}
+
+void RenderBox::addOverflowFromChild(RenderBox* child, const LayoutSize& delta)
+{
+    // Only propagate layout overflow from the child if the child isn't clipping its overflow.  If it is, then
+    // its overflow is internal to it, and we don't care about it.  layoutOverflowRectForPropagation takes care of this
+    // and just propagates the border box rect instead.
+    LayoutRect childLayoutOverflowRect = child->layoutOverflowRectForPropagation(style());
+    childLayoutOverflowRect.move(delta);
+    addLayoutOverflow(childLayoutOverflowRect);
+            
+    // Add in visual overflow from the child.  Even if the child clips its overflow, it may still
+    // have visual overflow of its own set from box shadows or reflections.  It is unnecessary to propagate this
+    // overflow if we are clipping our own overflow.
+    if (child->hasSelfPaintingLayer() || hasOverflowClip())
+        return;
+    LayoutRect childVisualOverflowRect = child->visualOverflowRectForPropagation(style());
+    childVisualOverflowRect.move(delta);
+    addVisualOverflow(childVisualOverflowRect);
+}
+
+void RenderBox::addLayoutOverflow(const LayoutRect& rect)
+{
+    LayoutRect clientBox = clientBoxRect();
+    if (clientBox.contains(rect) || rect.isEmpty())
+        return;
+    
+    // For overflow clip objects, we don't want to propagate overflow into unreachable areas.
+    LayoutRect overflowRect(rect);
+    if (hasOverflowClip() || isRenderView()) {
+        // Overflow is in the block's coordinate space and thus is flipped for horizontal-bt and vertical-rl 
+        // writing modes.  At this stage that is actually a simplification, since we can treat horizontal-tb/bt as the same
+        // and vertical-lr/rl as the same.
+        bool hasTopOverflow = !style()->isLeftToRightDirection() && !isHorizontalWritingMode();
+        bool hasLeftOverflow = !style()->isLeftToRightDirection() && isHorizontalWritingMode();
+        
+        if (!hasTopOverflow)
+            overflowRect.shiftYEdgeTo(max(overflowRect.y(), clientBox.y()));
+        else
+            overflowRect.shiftMaxYEdgeTo(min(overflowRect.maxY(), clientBox.maxY()));
+        if (!hasLeftOverflow)
+            overflowRect.shiftXEdgeTo(max(overflowRect.x(), clientBox.x()));
+        else
+            overflowRect.shiftMaxXEdgeTo(min(overflowRect.maxX(), clientBox.maxX()));
+        
+        // Now re-test with the adjusted rectangle and see if it has become unreachable or fully
+        // contained.
+        if (clientBox.contains(overflowRect) || overflowRect.isEmpty())
+            return;
+    }
+
+    if (!m_overflow)
+        m_overflow = adoptPtr(new RenderOverflow(clientBox, borderBoxRect()));
+    
+    m_overflow->addLayoutOverflow(overflowRect);
+}
+
+void RenderBox::addVisualOverflow(const LayoutRect& rect)
+{
+    LayoutRect borderBox = borderBoxRect();
+    if (borderBox.contains(rect) || rect.isEmpty())
+        return;
+        
+    if (!m_overflow)
+        m_overflow = adoptPtr(new RenderOverflow(clientBoxRect(), borderBox));
+    
+    m_overflow->addVisualOverflow(rect);
+}
+
+void RenderBox::clearLayoutOverflow()
+{
+    if (!m_overflow)
+        return;
+    
+    if (visualOverflowRect() == borderBoxRect()) {
+        m_overflow.clear();
+        return;
+    }
+    
+    m_overflow->resetLayoutOverflow(borderBoxRect());
+}
+
+static bool percentageLogicalHeightIsResolvable(const RenderBox* box)
+{
+    // In quirks mode, blocks with auto height are skipped, and we keep looking for an enclosing
+    // block that may have a specified height and then use it. In strict mode, this violates the
+    // specification, which states that percentage heights just revert to auto if the containing
+    // block has an auto height. We still skip anonymous containing blocks in both modes, though, and look
+    // only at explicit containers.
+    const RenderBlock* cb = box->containingBlock();
+    while (!cb->isRenderView() && !cb->isBody() && !cb->isTableCell() && !cb->isPositioned() && cb->style()->logicalHeight().isAuto()) {
+        if (!box->document()->inQuirksMode() && !cb->isAnonymousBlock())
+            break;
+        cb = cb->containingBlock();
+    }
+
+    // A positioned element that specified both top/bottom or that specifies height should be treated as though it has a height
+    // explicitly specified that can be used for any percentage computations.
+    // FIXME: We can't just check top/bottom here.
+    // https://bugs.webkit.org/show_bug.cgi?id=46500
+    bool isPositionedWithSpecifiedHeight = cb->isPositioned() && (!cb->style()->logicalHeight().isAuto() || (!cb->style()->top().isAuto() && !cb->style()->bottom().isAuto()));
+
+    // Table cells violate what the CSS spec says to do with heights.  Basically we
+    // don't care if the cell specified a height or not.  We just always make ourselves
+    // be a percentage of the cell's current content height.
+    if (cb->isTableCell())
+        return true;
+
+    // Otherwise we only use our percentage height if our containing block had a specified
+    // height.
+    if (cb->style()->logicalHeight().isFixed())
+        return true;
+    if (cb->style()->logicalHeight().isPercent() && !isPositionedWithSpecifiedHeight)
+        return percentageLogicalHeightIsResolvable(cb);
+    if (cb->isRenderView() || (cb->isBody() && box->document()->inQuirksMode()) || isPositionedWithSpecifiedHeight)
+        return true;
+    if (cb->isRoot() && box->isPositioned()) {
+        // Match the positioned objects behavior, which is that positioned objects will fill their viewport
+        // always.  Note we could only hit this case by recurring into computePercentageLogicalHeight on a positioned containing block.
+        return true;
+    }
+
+    return false;
+}
+
+bool RenderBox::hasUnsplittableScrollingOverflow() const
+{
+    // We will paginate as long as we don't scroll overflow in the pagination direction.
+    bool isHorizontal = isHorizontalWritingMode();
+    if ((isHorizontal && !scrollsOverflowY()) || (!isHorizontal && !scrollsOverflowX()))
+        return false;
+    
+    // We do have overflow. We'll still be willing to paginate as long as the block
+    // has auto logical height, auto or undefined max-logical-height and a zero or auto min-logical-height.
+    // Note this is just a heuristic, and it's still possible to have overflow under these
+    // conditions, but it should work out to be good enough for common cases. Paginating overflow
+    // with scrollbars present is not the end of the world and is what we used to do in the old model anyway.
+    return !style()->logicalHeight().isIntrinsicOrAuto()
+        || (!style()->logicalMaxHeight().isIntrinsicOrAuto() && !style()->logicalMaxHeight().isUndefined() && (!style()->logicalMaxHeight().isPercent() || percentageLogicalHeightIsResolvable(this)))
+        || (!style()->logicalMinHeight().isIntrinsicOrAuto() && style()->logicalMinHeight().isPositive() && (!style()->logicalMinHeight().isPercent() || percentageLogicalHeightIsResolvable(this)));
+}
+
+bool RenderBox::isUnsplittableForPagination() const
+{
+    return isReplaced() || hasUnsplittableScrollingOverflow() || (parent() && isWritingModeRoot());
+}
+
+LayoutUnit RenderBox::lineHeight(bool /*firstLine*/, LineDirectionMode direction, LinePositionMode /*linePositionMode*/) const
+{
+    if (isReplaced())
+        return direction == HorizontalLine ? m_marginTop + height() + m_marginBottom : m_marginRight + width() + m_marginLeft;
+    return 0;
+}
+
+LayoutUnit RenderBox::baselinePosition(FontBaseline baselineType, bool /*firstLine*/, LineDirectionMode direction, LinePositionMode /*linePositionMode*/) const
+{
+    if (isReplaced()) {
+        LayoutUnit result = direction == HorizontalLine ? m_marginTop + height() + m_marginBottom : m_marginRight + width() + m_marginLeft;
+        if (baselineType == AlphabeticBaseline)
+            return result;
+        return result - result / 2;
+    }
+    return 0;
+}
+
+
+RenderLayer* RenderBox::enclosingFloatPaintingLayer() const
+{
+    const RenderObject* curr = this;
+    while (curr) {
+        RenderLayer* layer = curr->hasLayer() && curr->isBox() ? toRenderBoxModelObject(curr)->layer() : 0;
+        if (layer && layer->isSelfPaintingLayer())
+            return layer;
+        curr = curr->parent();
+    }
+    return 0;
+}
+
+LayoutRect RenderBox::logicalVisualOverflowRectForPropagation(RenderStyle* parentStyle) const
+{
+    LayoutRect rect = visualOverflowRectForPropagation(parentStyle);
+    if (!parentStyle->isHorizontalWritingMode())
+        return rect.transposedRect();
+    return rect;
+}
+
+LayoutRect RenderBox::visualOverflowRectForPropagation(RenderStyle* parentStyle) const
+{
+    // If the writing modes of the child and parent match, then we don't have to 
+    // do anything fancy. Just return the result.
+    LayoutRect rect = visualOverflowRect();
+    if (parentStyle->writingMode() == style()->writingMode())
+        return rect;
+    
+    // We are putting ourselves into our parent's coordinate space.  If there is a flipped block mismatch
+    // in a particular axis, then we have to flip the rect along that axis.
+    if (style()->writingMode() == RightToLeftWritingMode || parentStyle->writingMode() == RightToLeftWritingMode)
+        rect.setX(width() - rect.maxX());
+    else if (style()->writingMode() == BottomToTopWritingMode || parentStyle->writingMode() == BottomToTopWritingMode)
+        rect.setY(height() - rect.maxY());
+
+    return rect;
+}
+
+LayoutRect RenderBox::logicalLayoutOverflowRectForPropagation(RenderStyle* parentStyle) const
+{
+    LayoutRect rect = layoutOverflowRectForPropagation(parentStyle);
+    if (!parentStyle->isHorizontalWritingMode())
+        return rect.transposedRect();
+    return rect;
+}
+
+LayoutRect RenderBox::layoutOverflowRectForPropagation(RenderStyle* parentStyle) const
+{
+    // Only propagate interior layout overflow if we don't clip it.
+    LayoutRect rect = borderBoxRect();
+    if (!hasOverflowClip())
+        rect.unite(layoutOverflowRect());
+
+    bool hasTransform = hasLayer() && layer()->transform();
+    if (isRelPositioned() || hasTransform) {
+        // If we are relatively positioned or if we have a transform, then we have to convert
+        // this rectangle into physical coordinates, apply relative positioning and transforms
+        // to it, and then convert it back.
+        flipForWritingMode(rect);
+        
+        if (hasTransform)
+            rect = layer()->currentTransform().mapRect(rect);
+
+        if (isRelPositioned())
+            rect.move(relativePositionOffsetX(), relativePositionOffsetY());
+        
+        // Now we need to flip back.
+        flipForWritingMode(rect);
+    }
+    
+    // If the writing modes of the child and parent match, then we don't have to 
+    // do anything fancy. Just return the result.
+    if (parentStyle->writingMode() == style()->writingMode())
+        return rect;
+    
+    // We are putting ourselves into our parent's coordinate space.  If there is a flipped block mismatch
+    // in a particular axis, then we have to flip the rect along that axis.
+    if (style()->writingMode() == RightToLeftWritingMode || parentStyle->writingMode() == RightToLeftWritingMode)
+        rect.setX(width() - rect.maxX());
+    else if (style()->writingMode() == BottomToTopWritingMode || parentStyle->writingMode() == BottomToTopWritingMode)
+        rect.setY(height() - rect.maxY());
+
+    return rect;
+}
+
+LayoutPoint RenderBox::flipForWritingModeForChild(const RenderBox* child, const LayoutPoint& point) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return point;
+    
+    // The child is going to add in its x() and y(), so we have to make sure it ends up in
+    // the right place.
+    if (isHorizontalWritingMode())
+        return LayoutPoint(point.x(), point.y() + height() - child->height() - (2 * child->y()));
+    return LayoutPoint(point.x() + width() - child->width() - (2 * child->x()), point.y());
+}
+
+void RenderBox::flipForWritingMode(IntRect& rect) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return;
+
+    if (isHorizontalWritingMode())
+        rect.setY(height() - rect.maxY());
+    else
+        rect.setX(width() - rect.maxX());
+}
+
+int RenderBox::flipForWritingMode(int position) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return position;
+    return logicalHeight() - position;
+}
+
+IntPoint RenderBox::flipForWritingMode(const IntPoint& position) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return position;
+    return isHorizontalWritingMode() ? IntPoint(position.x(), height() - position.y()) : IntPoint(width() - position.x(), position.y());
+}
+
+LayoutPoint RenderBox::flipForWritingModeIncludingColumns(const LayoutPoint& point) const
+{
+    if (!hasColumns() || !style()->isFlippedBlocksWritingMode())
+        return flipForWritingMode(point);
+    return toRenderBlock(this)->flipForWritingModeIncludingColumns(point);
+}
+
+IntSize RenderBox::flipForWritingMode(const IntSize& offset) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return offset;
+    return isHorizontalWritingMode() ? IntSize(offset.width(), height() - offset.height()) : IntSize(width() - offset.width(), offset.height());
+}
+
+FloatPoint RenderBox::flipForWritingMode(const FloatPoint& position) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return position;
+    return isHorizontalWritingMode() ? FloatPoint(position.x(), height() - position.y()) : FloatPoint(width() - position.x(), position.y());
+}
+
+void RenderBox::flipForWritingMode(FloatRect& rect) const
+{
+    if (!style()->isFlippedBlocksWritingMode())
+        return;
+
+    if (isHorizontalWritingMode())
+        rect.setY(height() - rect.maxY());
+    else
+        rect.setX(width() - rect.maxX());
+}
+
+LayoutPoint RenderBox::topLeftLocation() const
+{
+    RenderBlock* containerBlock = containingBlock();
+    if (!containerBlock || containerBlock == this)
+        return location();
+    return containerBlock->flipForWritingModeForChild(this, location());
+}
+
+LayoutSize RenderBox::topLeftLocationOffset() const
+{
+    RenderBlock* containerBlock = containingBlock();
+    if (!containerBlock || containerBlock == this)
+        return locationOffset();
+    
+    LayoutRect rect(frameRect());
+    containerBlock->flipForWritingMode(rect); // FIXME: This is wrong if we are an absolutely positioned object enclosed by a relative-positioned inline.
+    return LayoutSize(rect.x(), rect.y());
+}
+
+} // namespace WebCore