Implement Paint Containment

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 547 matching lines @@
     // on painting phases, so we need to update when either are updated.
     if (layerConfigChanged || maskLayerChanged)
         updatePaintingPhases();
 
     return layerConfigChanged;
 }
 
 static IntRect clipBox(LayoutBox* layoutObject)
 {
     LayoutRect result = LayoutRect(LayoutRect::infiniteIntRect());
-    if (layoutObject->hasOverflowClip())
+    if (layoutObject->hasOverflowClip() || layoutObject->style()->containsPaint())
         result = layoutObject->overflowClipRect(LayoutPoint());
 
     if (layoutObject->hasClip())
         result.intersect(layoutObject->clipRect(LayoutPoint()));
 
     return pixelSnappedIntRect(result);
 }
 
 static LayoutPoint computeOffsetFromCompositedAncestor(const PaintLayer* layer, const PaintLayer* compositedAncestor)
 {
@@ skipping 1986 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink