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

gpu/command_buffer/client/gles2_implementation.h

 // Copyright (c) 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 GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 199 matching lines @@
 
   virtual void DisableVertexAttribArray(GLuint index) OVERRIDE;
   virtual void EnableVertexAttribArray(GLuint index) OVERRIDE;
   virtual void GetVertexAttribfv(
       GLuint index, GLenum pname, GLfloat* params) OVERRIDE;
   virtual void GetVertexAttribiv(
       GLuint index, GLenum pname, GLint* params) OVERRIDE;
 
   // ContextSupport implementation.
   virtual void Swap() OVERRIDE;
-  virtual void PartialSwapBuffers(gfx::Rect sub_buffer) OVERRIDE;
+  virtual void PartialSwapBuffers(const gfx::Rect& sub_buffer) OVERRIDE;
   virtual void SetSwapBuffersCompleteCallback(
       const base::Closure& swap_buffers_complete_callback)
           OVERRIDE;
 
   void GetProgramInfoCHROMIUMHelper(GLuint program, std::vector<int8>* result);
   GLint GetAttribLocationHelper(GLuint program, const char* name);
   GLint GetUniformLocationHelper(GLuint program, const char* name);
   bool GetActiveAttribHelper(
       GLuint program, GLuint index, GLsizei bufsize, GLsizei* length,
       GLint* size, GLenum* type, char* name);
@@ skipping 523 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_