Don't force full repaint on size change in style

Source/core/rendering/style/RenderStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 405 matching lines @@
 
 bool RenderStyle::diffNeedsFullLayoutAndRepaint(const RenderStyle& other) const
 {
     // FIXME: Not all cases in this method need both full layout and repaint.
     // Should move cases into diffNeedsFullLayout() if
     // - don't need repaint at all;
     // - or the renderer knows how to exactly repaint caused by the layout change
     //   instead of forced full repaint.
 
     if (m_box.get() != other.m_box.get()) {
-        if (m_box->width() != other.m_box->width()
-            || m_box->minWidth() != other.m_box->minWidth()
-            || m_box->maxWidth() != other.m_box->maxWidth()
-            || m_box->height() != other.m_box->height()
-            || m_box->minHeight() != other.m_box->minHeight()
-            || m_box->maxHeight() != other.m_box->maxHeight())
-            return true;
-
         if (m_box->verticalAlign() != other.m_box->verticalAlign())
             return true;
 
         if (m_box->boxSizing() != other.m_box->boxSizing())
             return true;
     }
 
     if (surround.get() != other.surround.get()) {
         if (surround->margin != other.surround->margin)
             return true;
@@ skipping 163 matching lines @@
         return true;
     }
 
     // Movement of non-static-positioned object is special cased in RenderStyle::visualInvalidationDiff().
 
     return false;
 }
 
 bool RenderStyle::diffNeedsFullLayout(const RenderStyle& other) const
 {
+    if (m_box.get() != other.m_box.get()) {
+        if (m_box->width() != other.m_box->width()
+            || m_box->minWidth() != other.m_box->minWidth()
+            || m_box->maxWidth() != other.m_box->maxWidth()
+            || m_box->height() != other.m_box->height()
+            || m_box->minHeight() != other.m_box->minHeight()
+            || m_box->maxHeight() != other.m_box->maxHeight())
+            return true;
+    }
+
     return false;
 }
 
 bool RenderStyle::diffNeedsRepaintLayer(const RenderStyle& other) const
 {
     if (position() != StaticPosition && (visual->clip != other.visual->clip || visual->hasClip != other.visual->hasClip))
         return true;
 
     if (rareNonInheritedData.get() != other.rareNonInheritedData.get()) {
         if (RuntimeEnabledFeatures::cssCompositingEnabled()
@@ skipping 1078 matching lines @@
     // right
     radiiSum = radii.topRight().height() + radii.bottomRight().height();
     if (radiiSum > rect.height())
         factor = std::min(rect.height() / radiiSum, factor);
 
     ASSERT(factor <= 1);
     return factor;
 }
 
 } // namespace WebCore