[#7] Pass gfx structs by const ref (gfx::Size)

cc/layers/ui_resource_layer_impl.cc

 // Copyright 2013 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.
 
 #include "cc/layers/ui_resource_layer_impl.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
 #include "cc/layers/quad_sink.h"
@@ skipping 31 matching lines @@
   layer_impl->SetVertexOpacity(vertex_opacity_);
 }
 
 void UIResourceLayerImpl::SetUIResourceId(UIResourceId uid) {
   if (uid == ui_resource_id_)
     return;
   ui_resource_id_ = uid;
   NoteLayerPropertyChanged();
 }
 
-void UIResourceLayerImpl::SetImageBounds(gfx::Size image_bounds) {
+void UIResourceLayerImpl::SetImageBounds(const gfx::Size& image_bounds) {
   // This check imposes an ordering on the call sequence.  An UIResource must
   // exist before SetImageBounds can be called.
   DCHECK(ui_resource_id_);
 
   if (image_bounds_ == image_bounds)
     return;
 
   image_bounds_ = image_bounds;
 
   NoteLayerPropertyChanged();
@@ skipping 85 matching lines @@
   list->AppendDouble(vertex_opacity_[3]);
   result->Set("VertexOpacity", list);
 
   result->Set("UVTopLeft", MathUtil::AsValue(uv_top_left_).release());
   result->Set("UVBottomRight", MathUtil::AsValue(uv_bottom_right_).release());
 
   return result;
 }
 
 }  // namespace cc