ui: Prefer +/- operators to apply offsets.

ui/gfx/point.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_POINT_H_
 #define UI_GFX_POINT_H_
 
 #include "ui/base/ui_export.h"
 #include "ui/gfx/point_base.h"
 #include "ui/gfx/point_f.h"
@@ skipping 56 matching lines @@
   return result;
 }
 
 inline Point operator-(const Point& lhs, const Vector2d& rhs) {
   Point result(lhs);
   result -= rhs;
   return result;
 }
 
 inline Vector2d operator-(const Point& lhs, const Point& rhs) {
-  return lhs.OffsetFrom(rhs);
+  return Vector2d(lhs.x() - rhs.x(), lhs.y() - rhs.y());
 }
 
 inline Point PointAtOffsetFromOrigin(const Vector2d& offset_from_origin) {
   return Point(offset_from_origin.x(), offset_from_origin.y());
 }
 
 #if !defined(COMPILER_MSVC)
 extern template class PointBase<Point, int, Vector2d>;
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_POINT_H_