Avoid RenderObject::paintInvalidationForWholeRenderer() if possible

Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 286 matching lines @@
         toWebGLRenderingContext(m_context.get())->reshape(width(), height());
 
     if (RenderObject* renderer = this->renderer()) {
         if (renderer->isCanvas()) {
             if (oldSize != size()) {
                 toRenderHTMLCanvas(renderer)->canvasSizeChanged();
                 if (renderBox() && renderBox()->hasAcceleratedCompositing())
                     renderBox()->contentChanged(CanvasChanged);
             }
             if (hadImageBuffer)
-                renderer->paintInvalidationForWholeRenderer();
+                renderer->setShouldDoFullPaintInvalidation(true);
         }
     }
 
     WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator end = m_observers.end();
     for (WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
         (*it)->canvasResized(this);
 }
 
 bool HTMLCanvasElement::paintsIntoCanvasBuffer() const
 {
@@ skipping 422 matching lines @@
 {
     return !originClean();
 }
 
 FloatSize HTMLCanvasElement::sourceSize() const
 {
     return FloatSize(width(), height());
 }
 
 }