ui/gfx: Make gfx::Size::GetArea use checked math.

ui/gfx/geometry/size.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_GEOMETRY_SIZE_H_
 #define UI_GFX_GEOMETRY_SIZE_H_
 
 #include <iosfwd>
 #include <string>
 
@@ skipping 29 matching lines @@
 #elif defined(OS_MACOSX)
   CGSize ToCGSize() const;
 #endif
 
   int width() const { return width_; }
   int height() const { return height_; }
 
   void set_width(int width) { width_ = width < 0 ? 0 : width; }
   void set_height(int height) { height_ = height < 0 ? 0 : height; }
 
+  // This call will CHECK if the area of this size would overflow int.
   int GetArea() const;
 
   void SetSize(int width, int height) {
     set_width(width);
     set_height(height);
   }
 
   void Enlarge(int grow_width, int grow_height);
 
   void SetToMin(const Size& other);
@@ skipping 31 matching lines @@
                                    float y_scale);
 GFX_EXPORT Size ScaleToFlooredSize(const Size& size, float x_scale);
 GFX_EXPORT Size ScaleToRoundedSize(const Size& size,
                                    float x_scale,
                                    float y_scale);
 GFX_EXPORT Size ScaleToRoundedSize(const Size& size, float x_scale);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GEOMETRY_SIZE_H_