Make adding and subtracting gfx:: point types simpler.

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"
 
 #if defined(OS_WIN)
 typedef unsigned long DWORD;
 typedef struct tagPOINT POINT;
 #elif defined(OS_IOS)
 #include <CoreGraphics/CoreGraphics.h>
 #elif defined(OS_MACOSX)
 #include <ApplicationServices/ApplicationServices.h>
 #endif
 
@@ skipping 16 matching lines @@
 #endif
 
   ~Point() {}
 
 #if defined(OS_WIN)
   POINT ToPOINT() const;
 #elif defined(OS_MACOSX)
   CGPoint ToCGPoint() const;
 #endif
 
+  PointF ToPointF() const {
+    return PointF(x(), y());
+  }
+
   // Returns a string representation of point.
   std::string ToString() const;
 };
 
+inline Point operator+(Point lhs, Point rhs) {
+  return lhs.Add(rhs);
+}
+
+inline Point operator-(Point lhs, Point rhs) {
+  return lhs.Subtract(rhs);
+}
+
 #if !defined(COMPILER_MSVC)
 extern template class PointBase<Point, int>;
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_POINT_H_