Add Vector2d classes that represent offsets, instead of using Point.

ui/gfx/rect_f.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_RECT_F_H_
 #define UI_GFX_RECT_F_H_
 
 #include <string>
 
 #include "ui/gfx/point_f.h"
 #include "ui/gfx/rect_base.h"
 #include "ui/gfx/size_f.h"
+#include "ui/gfx/vector2d_f.h"
 
 namespace gfx {
 
 class InsetsF;
 
 // A floating version of gfx::Rect.
-class UI_EXPORT RectF : public RectBase<RectF, PointF, SizeF, InsetsF, float> {
+class UI_EXPORT RectF
+    : public RectBase<RectF, PointF, SizeF, InsetsF, Vector2dF, float> {
  public:
   RectF();
   RectF(float width, float height);
   RectF(float x, float y, float width, float height);
   explicit RectF(const gfx::SizeF& size);
   RectF(const gfx::PointF& origin, const gfx::SizeF& size);
 
   ~RectF();
 
   /// Scales the rectangle by |scale|.
@@ skipping 22 matching lines @@
 UI_EXPORT RectF IntersectRects(const RectF& a, const RectF& b);
 UI_EXPORT RectF UnionRects(const RectF& a, const RectF& b);
 UI_EXPORT RectF SubtractRects(const RectF& a, const RectF& b);
 UI_EXPORT RectF ScaleRect(const RectF& r, float x_scale, float y_scale);
 
 inline RectF ScaleRect(const RectF& r, float scale) {
   return ScaleRect(r, scale, scale);
 }
 
 #if !defined(COMPILER_MSVC)
-extern template class RectBase<RectF, PointF, SizeF, InsetsF, float>;
+extern template class RectBase<RectF, PointF, SizeF, InsetsF, Vector2dF, float>;
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RECT_F_H_