Fix pixel snapping issues when layers become composited

Source/platform/geometry/LayoutSize.h

 /*
  * Copyright (c) 2012, Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 108 matching lines @@
 
     LayoutSize fitToAspectRatio(const LayoutSize& aspectRatio, AspectRatioFit fit) const
     {
         float heightScale = height().toFloat() / aspectRatio.height().toFloat();
         float widthScale = width().toFloat() / aspectRatio.width().toFloat();
         if ((widthScale > heightScale) != (fit == AspectRatioFitGrow))
             return LayoutSize(height() * aspectRatio.width() / aspectRatio.height(), height());
         return LayoutSize(width(), width() * aspectRatio.height() / aspectRatio.width());
     }
 
+    LayoutSize fraction() const
+    {
+        return LayoutSize(m_width.fraction(), m_height.fraction());
+    }
+
 private:
     LayoutUnit m_width, m_height;
 };
 
 inline LayoutSize& operator+=(LayoutSize& a, const LayoutSize& b)
 {
     a.setWidth(a.width() + b.width());
     a.setHeight(a.height() + b.height());
     return a;
 }
@@ skipping 41 matching lines @@
 }
 
 inline LayoutSize roundedLayoutSize(const FloatSize& s)
 {
     return LayoutSize(s);
 }
 
 } // namespace WebCore
 
 #endif // LayoutSize_h