1 files changed, 13 insertions, 2 deletions
diff --git a/Source/WebCore/rendering/RenderLayerBacking.cpp b/Source/WebCore/rendering/RenderLayerBacking.cpp
index ee39912a9..1085eabc0 100644
--- a/Source/WebCore/rendering/RenderLayerBacking.cpp
+++ b/Source/WebCore/rendering/RenderLayerBacking.cpp
@@ -267,7 +267,7 @@ void RenderLayerBacking::updateCompositedBounds()
         LayoutRect clippingBounds = view->unscaledDocumentRect();
 
         if (m_owningLayer != rootLayer)
-            clippingBounds.intersect(m_owningLayer->backgroundClipRect(rootLayer, 0, true).rect()); // FIXME: Incorrect for CSS regions.
+            clippingBounds.intersect(m_owningLayer->backgroundClipRect(rootLayer, 0, AbsoluteClipRects).rect()); // FIXME: Incorrect for CSS regions.
 
         LayoutPoint delta;
         m_owningLayer->convertToLayerCoords(rootLayer, delta);
@@ -465,7 +465,7 @@ void RenderLayerBacking::updateGraphicsLayerGeometry()
         // Call calculateRects to get the backgroundRect which is what is used to clip the contents of this
         // layer. Note that we call it with temporaryClipRects = true because normally when computing clip rects
         // for a compositing layer, rootLayer is the layer itself.
-        IntRect parentClipRect = pixelSnappedIntRect(m_owningLayer->backgroundClipRect(compAncestor, 0, true).rect()); // FIXME: Incorrect for CSS regions.
+        IntRect parentClipRect = pixelSnappedIntRect(m_owningLayer->backgroundClipRect(compAncestor, 0, TemporaryClipRects).rect()); // FIXME: Incorrect for CSS regions.
         ASSERT(parentClipRect != PaintInfo::infiniteRect());
         m_ancestorClippingLayer->setPosition(FloatPoint() + (parentClipRect.location() - graphicsLayerParentLocation));
         m_ancestorClippingLayer->setSize(parentClipRect.size());
@@ -1112,6 +1112,17 @@ bool RenderLayerBacking::paintsIntoWindow() const
     return false;
 }
 
+void RenderLayerBacking::setRequiresOwnBackingStore(bool flag)
+{
+    if (flag == m_requiresOwnBackingStore)
+        return;
+    
+    // This affects the answer to paintsIntoCompositedAncestor(), which in turn affects
+    // cached clip rects, so when it changes we have to clear clip rects on descendants.
+    m_owningLayer->clearClipRectsIncludingDescendants(PaintingClipRects);
+    m_requiresOwnBackingStore = flag;
+}
+
 void RenderLayerBacking::setContentsNeedDisplay()
 {
     ASSERT(!paintsIntoCompositedAncestor());