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

cc/output/output_surface_client.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_CLIENT_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_CLIENT_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
@@ skipping 12 matching lines @@
 struct ManagedMemoryPolicy;
 
 class CC_EXPORT OutputSurfaceClient {
  public:
   // Called to synchronously re-initialize using the Context3D. Upon returning
   // the compositor should be able to draw using GL what was previously
   // committed.
   virtual bool DeferredInitialize(
       scoped_refptr<ContextProvider> offscreen_context_provider) = 0;
   virtual void ReleaseGL() = 0;
-  virtual void SetNeedsRedrawRect(gfx::Rect damage_rect) = 0;
+  virtual void SetNeedsRedrawRect(const gfx::Rect& damage_rect) = 0;
   virtual void BeginImplFrame(const BeginFrameArgs& args) = 0;
   virtual void DidSwapBuffers() = 0;
   virtual void OnSwapBuffersComplete() = 0;
   virtual void ReclaimResources(const CompositorFrameAck* ack) = 0;
   virtual void DidLoseOutputSurface() = 0;
   virtual 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) = 0;
   virtual void SetMemoryPolicy(const ManagedMemoryPolicy& policy) = 0;
   // If set, |callback| will be called subsequent to each new tree activation,
   // regardless of the compositor visibility or damage. |callback| must remain
   // valid for the lifetime of the OutputSurfaceClient or until unregisted --
   // use SetTreeActivationCallback(base::Closure()) to unregister it.
   virtual void SetTreeActivationCallback(const base::Closure& callback) = 0;
 
  protected:
   virtual ~OutputSurfaceClient() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_CLIENT_H_