[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/base/tiling_data.h

 // Copyright 2010 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 CC_BASE_TILING_DATA_H_
 #define CC_BASE_TILING_DATA_H_
 
 #include <utility>
 
 #include "base/basictypes.h"
@@ skipping 71 matching lines @@
     }
 
     const TilingData* tiling_data_;
     int index_x_;
     int index_y_;
   };
 
   // Iterate through all indices whose bounds + border intersect with |rect|.
   class CC_EXPORT Iterator : public BaseIterator {
    public:
-    Iterator(const TilingData* tiling_data, gfx::Rect rect);
+    Iterator(const TilingData* tiling_data, const gfx::Rect& tiling_rect);
     Iterator& operator++();
 
    private:
     int left_;
     int right_;
     int bottom_;
   };
 
   // Iterate through all indices whose bounds + border intersect with
   // |consider| but which also do not intersect with |ignore|.
   class CC_EXPORT DifferenceIterator : public BaseIterator {
    public:
     DifferenceIterator(
       const TilingData* tiling_data,
-      gfx::Rect consider,
-      gfx::Rect ignore);
+      const gfx::Rect& consider_rect,
+      const gfx::Rect& ignore_rect);
     DifferenceIterator& operator++();
 
    private:
     bool in_ignore_rect() const {
      return index_x_ >= ignore_left_ && index_x_ <= ignore_right_ &&
        index_y_ >= ignore_top_ && index_y_ <= ignore_bottom_;
     }
 
     int consider_left_;
     int consider_top_;
@@ skipping 20 matching lines @@
   int border_texels_;
 
   // These are computed values.
   int num_tiles_x_;
   int num_tiles_y_;
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_TILING_DATA_H_