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

ui/gfx/vector2d_conversions.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_VECTOR2D_CONVERSIONS_H_
+#define UI_GFX_VECTOR2D_CONVERSIONS_H_
+
+#include "ui/gfx/vector2d.h"
+#include "ui/gfx/vector2d_f.h"
+
+namespace gfx {
+
+// Returns a Vector2d with each component from the input Vector2dF floored.
+UI_EXPORT Vector2d ToFlooredVector2d(const Vector2dF& vector2d);
+
+// Returns a Vector2d with each component from the input Vector2dF ceiled.
+UI_EXPORT Vector2d ToCeiledVector2d(const Vector2dF& vector2d);
+
+// Returns a Vector2d with each component from the input Vector2dF rounded.
+UI_EXPORT Vector2d ToRoundedVector2d(const Vector2dF& vector2d);
+
+}  // namespace gfx
+
+#endif  // UI_GFX_VECTOR2D_CONVERSIONS_H_