Change Widget subclasses to use a CullRect instead of an IntRect for painting.

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 44 matching lines @@
 #include "core/paint/ScrollableAreaPainter.h"
 #include "core/paint/TransformRecorder.h"
 #include "core/plugins/PluginView.h"
 #include "platform/LengthFunctions.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/BitmapImage.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/ClipDisplayItem.h"
+#include "platform/graphics/paint/CullRect.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "platform/graphics/paint/TransformDisplayItem.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 static IntRect clipBox(LayoutBox* layoutObject);
@@ skipping 2086 matching lines @@
 
 static void paintScrollbar(const Scrollbar* scrollbar, GraphicsContext& context, const IntRect& clip)
 {
     if (!scrollbar)
         return;
 
     const IntRect& scrollbarRect = scrollbar->frameRect();
     TransformRecorder transformRecorder(context, *scrollbar, AffineTransform::translation(-scrollbarRect.x(), -scrollbarRect.y()));
     IntRect transformedClip = clip;
     transformedClip.moveBy(scrollbarRect.location());
-    scrollbar->paint(&context, transformedClip);
+    scrollbar->paint(&context, CullRect(transformedClip));
 }
 
 static const int kPixelDistanceToRecord = 4000;
 
 IntRect CompositedLayerMapping::computeInterestRect(const GraphicsLayer* graphicsLayer, LayoutObject* owningLayoutObject)
 {
     FloatRect graphicsLayerBounds(FloatPoint(), graphicsLayer->size());
 
     // Start with the bounds of the graphics layer in the space of the owning LayoutObject.
     FloatRect graphicsLayerBoundsInObjectSpace(graphicsLayerBounds);
@@ skipping 278 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink