[#3] Pass gfx structs by const ref (gfx::SizeF)

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 582 matching lines @@
     is_replica = true;
     layer->render_surface()->AppendQuads(&quad_culler,
                                          append_quads_data,
                                          is_replica,
                                          contributing_render_pass->id);
   }
 }
 
 static void AppendQuadsToFillScreen(
     ResourceProvider::ResourceId overhang_resource_id,
-    gfx::SizeF overhang_resource_scaled_size,
+    const gfx::SizeF& overhang_resource_scaled_size,
     const gfx::Rect& root_scroll_layer_rect,
     RenderPass* target_render_pass,
     LayerImpl* root_layer,
     SkColor screen_background_color,
     const OcclusionTrackerImpl& occlusion_tracker) {
   if (!root_layer || !SkColorGetA(screen_background_color))
     return;
 
   Region fill_region = occlusion_tracker.ComputeVisibleRegionInScreen();
   if (fill_region.IsEmpty())
@@ skipping 2294 matching lines @@
   swap_promise_monitor_.erase(monitor);
 }
 
 void LayerTreeHostImpl::NotifySwapPromiseMonitorsOfSetNeedsRedraw() {
   std::set<SwapPromiseMonitor*>::iterator it = swap_promise_monitor_.begin();
   for (; it != swap_promise_monitor_.end(); it++)
     (*it)->OnSetNeedsRedrawOnImpl();
 }
 
 }  // namespace cc