[#4] Pass gfx structs by const ref (gfx::PointF)

cc/layers/ui_resource_layer.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.h"
 
 #include "cc/layers/ui_resource_layer_impl.h"
 #include "cc/resources/prioritized_resource.h"
 #include "cc/resources/resource_update.h"
 #include "cc/resources/resource_update_queue.h"
@@ skipping 54 matching lines @@
   vertex_opacity_[3] = 1.0f;
 }
 
 UIResourceLayer::~UIResourceLayer() {}
 
 scoped_ptr<LayerImpl> UIResourceLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return UIResourceLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
 }
 
-void UIResourceLayer::SetUV(gfx::PointF top_left, gfx::PointF bottom_right) {
+void UIResourceLayer::SetUV(const gfx::PointF& top_left,
+                            const gfx::PointF& bottom_right) {
   if (uv_top_left_ == top_left && uv_bottom_right_ == bottom_right)
     return;
   uv_top_left_ = top_left;
   uv_bottom_right_ = bottom_right;
   SetNeedsCommit();
 }
 
 void UIResourceLayer::SetVertexOpacity(float bottom_left,
                                        float top_left,
                                        float top_right,
@@ skipping 70 matching lines @@
     gfx::Size image_size =
         layer_tree_host()->GetUIResourceSize(ui_resource_holder_->id());
     layer_impl->SetUIResourceId(ui_resource_holder_->id());
     layer_impl->SetImageBounds(image_size);
     layer_impl->SetUV(uv_top_left_, uv_bottom_right_);
     layer_impl->SetVertexOpacity(vertex_opacity_);
   }
 }
 
 }  // namespace cc