Fix pixel snapping issues when layers become composited

Source/core/platform/graphics/LayoutPoint.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 64 matching lines @@
     void clampNegativeToZero()
     {
         *this = expandedTo(zero());
     }
 
     LayoutPoint transposedPoint() const
     {
         return LayoutPoint(m_y, m_x);
     }
 
+    LayoutPoint fraction() const
+    {
+        return LayoutPoint(m_x.fraction(), m_y.fraction());
+    }
+
 private:
     LayoutUnit m_x, m_y;
 };
 
 inline LayoutPoint& operator+=(LayoutPoint& a, const LayoutSize& b)
 {
     a.move(b.width(), b.height());
     return a;
 }
 
@@ skipping 100 matching lines @@
 
 inline LayoutPoint flooredLayoutPoint(const FloatSize& s)
 {
     return flooredLayoutPoint(FloatPoint(s));
 }
 
 
 } // namespace WebCore
 
 #endif // LayoutPoint_h