Use updated interest rect when layer needs repainting.

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 2388 matching lines @@
     if (!needsRepaint(*graphicsLayer) && previousInterestRect == wholeLayerRect)
         return previousInterestRect;
 
     // Paint the whole layer if "mainFrameClipsContent" is false, meaning that WebPreferences::record_whole_document is true.
     bool shouldPaintWholePage = !m_owningLayer.layoutObject()->document().settings()->mainFrameClipsContent();
     if (shouldPaintWholePage
         || (graphicsLayer != m_graphicsLayer.get() && graphicsLayer != m_squashingLayer.get() && graphicsLayer != m_scrollingContentsLayer.get()))
         return wholeLayerRect;
 
     IntRect newInterestRect = recomputeInterestRect(graphicsLayer);
-    if (interestRectChangedEnoughToRepaint(previousInterestRect, newInterestRect, expandedIntSize(graphicsLayer->size())))
+    if (needsRepaint(*graphicsLayer) || interestRectChangedEnoughToRepaint(previousInterestRect, newInterestRect, expandedIntSize(graphicsLayer->size())))
         return newInterestRect;
     return previousInterestRect;
 }
 
 LayoutSize CompositedLayerMapping::subpixelAccumulation() const
 {
     return m_owningLayer.subpixelAccumulation();
 }
 
 bool CompositedLayerMapping::needsRepaint(const GraphicsLayer& graphicsLayer) const
@@ skipping 277 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink