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

cc/output/output_surface.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_OUTPUT_SURFACE_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_H_
 
 #include <deque>
 
 #include "base/basictypes.h"
@@ skipping 157 matching lines @@
   int pending_swap_buffers_;
   bool needs_begin_impl_frame_;
   bool client_ready_for_begin_impl_frame_;
 
   // This stores a BeginImplFrame that we couldn't process immediately,
   // but might process retroactively in the near future.
   BeginFrameArgs skipped_begin_impl_frame_args_;
 
   // Forwarded to OutputSurfaceClient but threaded through OutputSurface
   // first so OutputSurface has a chance to update the FrameRateController
-  void SetNeedsRedrawRect(gfx::Rect damage_rect);
+  void SetNeedsRedrawRect(const gfx::Rect& damage_rect);
   void BeginImplFrame(const BeginFrameArgs& args);
   void DidSwapBuffers();
   void OnSwapBuffersComplete();
   void ReclaimResources(const CompositorFrameAck* ack);
   void DidLoseOutputSurface();
   void SetExternalStencilTest(bool enabled);
   void SetExternalDrawConstraints(const gfx::Transform& transform,
-                                  gfx::Rect viewport,
-                                  gfx::Rect clip,
+                                  const gfx::Rect& viewport,
+                                  const gfx::Rect& clip,
                                   bool valid_for_tile_management);
 
   // virtual for testing.
   virtual base::TimeTicks RetroactiveBeginImplFrameDeadline();
   virtual void PostCheckForRetroactiveBeginImplFrame();
   void CheckForRetroactiveBeginImplFrame();
 
  private:
   OutputSurfaceClient* client_;
 
@@ skipping 13 matching lines @@
   std::deque<unsigned> available_gpu_latency_query_ids_;
   std::deque<unsigned> pending_gpu_latency_query_ids_;
   RollingTimeDeltaHistory gpu_latency_history_;
 
   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_