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

cc/resources/resource_provider.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_RESOURCES_RESOURCE_PROVIDER_H_
 #define CC_RESOURCES_RESOURCE_PROVIDER_H_
 
 #include <deque>
 #include <set>
 #include <string>
@@ skipping 117 matching lines @@
   ResourceId CreateResourceFromTextureMailbox(
       const TextureMailbox& mailbox,
       scoped_ptr<SingleReleaseCallback> release_callback);
 
   void DeleteResource(ResourceId id);
 
   // Update pixels from image, copying source_rect (in image) to dest_offset (in
   // the resource).
   void SetPixels(ResourceId id,
                  const uint8_t* image,
-                 gfx::Rect image_rect,
-                 gfx::Rect source_rect,
+                 const gfx::Rect& image_rect,
+                 const gfx::Rect& source_rect,
                  gfx::Vector2d dest_offset);
 
   // Check upload status.
   size_t NumBlockingUploads();
   void MarkPendingUploadsAsNonBlocking();
   size_t EstimatedUploadsPerTick();
   void FlushUploads();
   void ReleaseCachedData();
   base::TimeTicks EstimatedUploadCompletionTime(size_t uploads_per_tick);
 
@@ skipping 401 matching lines @@
   return format_gl_data_format[format];
 }
 
 inline GLenum GLInternalFormat(ResourceFormat format) {
   return GLDataFormat(format);
 }
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_