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

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 44 matching lines @@
   DCHECK(ui_resource_id_);
 
   if (image_bounds_ == image_bounds)
     return;
 
   image_bounds_ = image_bounds;
 
   NoteLayerPropertyChanged();
 }
 
-void UIResourceLayerImpl::SetUV(gfx::PointF top_left,
-                                gfx::PointF bottom_right) {
+void UIResourceLayerImpl::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;
   NoteLayerPropertyChanged();
 }
 
 void UIResourceLayerImpl::SetVertexOpacity(const float vertex_opacity[4]) {
   if (vertex_opacity_[0] == vertex_opacity[0] &&
       vertex_opacity_[1] == vertex_opacity[1] &&
@@ skipping 71 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