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

cc/layers/render_surface_impl.h

 // Copyright 2011 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_LAYERS_RENDER_SURFACE_IMPL_H_
 #define CC_LAYERS_RENDER_SURFACE_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 83 matching lines @@
   void SetScreenSpaceTransformsAreAnimating(bool animating) {
     screen_space_transforms_are_animating_ = animating;
   }
   bool screen_space_transforms_are_animating() const {
     return screen_space_transforms_are_animating_;
   }
 
   void SetIsClipped(bool is_clipped) { is_clipped_ = is_clipped; }
   bool is_clipped() const { return is_clipped_; }
 
-  void SetClipRect(gfx::Rect clip_rect);
+  void SetClipRect(const gfx::Rect& clip_rect);
   gfx::Rect clip_rect() const { return clip_rect_; }
 
   // When false, the RenderSurface does not contribute to another target
   // RenderSurface that is being drawn for the current frame. It could still be
   // drawn to as a target, but its output will not be a part of any other
   // surface.
   bool contributes_to_drawn_surface() const {
     return contributes_to_drawn_surface_;
   }
   void set_contributes_to_drawn_surface(bool contributes_to_drawn_surface) {
     contributes_to_drawn_surface_ = contributes_to_drawn_surface;
   }
 
   bool ContentsChanged() const;
 
-  void SetContentRect(gfx::Rect content_rect);
+  void SetContentRect(const gfx::Rect& content_rect);
   gfx::Rect content_rect() const { return content_rect_; }
 
   LayerImplList& layer_list() { return layer_list_; }
   void AddContributingDelegatedRenderPassLayer(LayerImpl* layer);
   void ClearLayerLists();
 
   int OwningLayerId() const;
 
   void ResetPropertyChangedFlag() { surface_property_changed_ = false; }
   bool SurfacePropertyChanged() const;
@@ skipping 45 matching lines @@
   int target_render_surface_layer_index_history_;
   int current_layer_index_history_;
 
   friend struct LayerIteratorActions;
 
   DISALLOW_COPY_AND_ASSIGN(RenderSurfaceImpl);
 };
 
 }  // namespace cc
 #endif  // CC_LAYERS_RENDER_SURFACE_IMPL_H_