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

cc/output/delegating_renderer.h

 // Copyright 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 CC_OUTPUT_DELEGATING_RENDERER_H_
 #define CC_OUTPUT_DELEGATING_RENDERER_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 13 matching lines @@
       ResourceProvider* resource_provider);
   virtual ~DelegatingRenderer();
 
   virtual const RendererCapabilities& Capabilities() const OVERRIDE;
 
   virtual bool CanReadPixels() const OVERRIDE;
 
   virtual void DrawFrame(RenderPassList* render_passes_in_draw_order,
                          ContextProvider* offscreen_context_provider,
                          float device_scale_factor,
-                         gfx::Rect device_viewport_rect,
-                         gfx::Rect device_clip_rect,
+                         const gfx::Rect& device_viewport_rect,
+                         const gfx::Rect& device_clip_rect,
                          bool allow_partial_swap,
                          bool disable_picture_quad_image_filtering) OVERRIDE;
 
   virtual void Finish() OVERRIDE {}
 
   virtual void SwapBuffers(const CompositorFrameMetadata& metadata) OVERRIDE;
   virtual void ReceiveSwapBuffersAck(const CompositorFrameAck&) OVERRIDE;
 
-  virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) OVERRIDE;
+  virtual void GetFramebufferPixels(void* pixels,
+                                    const gfx::Rect& rect) OVERRIDE;
 
   virtual bool IsContextLost() OVERRIDE;
 
   virtual void SetVisible(bool visible) OVERRIDE;
 
   virtual void SendManagedMemoryStats(size_t bytes_visible,
                                       size_t bytes_visible_and_nearby,
                                       size_t bytes_allocated) OVERRIDE;
 
  private:
   DelegatingRenderer(RendererClient* client,
                      const LayerTreeSettings* settings,
                      OutputSurface* output_surface,
                      ResourceProvider* resource_provider);
   bool Initialize();
 
   OutputSurface* output_surface_;
   ResourceProvider* resource_provider_;
   RendererCapabilities capabilities_;
   scoped_ptr<DelegatedFrameData> delegated_frame_data_;
   bool visible_;
 
   DISALLOW_COPY_AND_ASSIGN(DelegatingRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_DELEGATING_RENDERER_H_