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

cc/trees/quad_culler.cc

 // 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.
 
 #include "cc/trees/quad_culler.h"
 
 #include "cc/debug/debug_colors.h"
 #include "cc/debug/overdraw_metrics.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/layer_impl.h"
@@ skipping 24 matching lines @@
     scoped_ptr<SharedQuadState> shared_quad_state) {
   // TODO(danakj): If all quads are culled for the shared_quad_state, we can
   // drop it from the list.
   current_shared_quad_state_ = shared_quad_state.get();
   shared_quad_state_list_->push_back(shared_quad_state.Pass());
   return current_shared_quad_state_;
 }
 
 static inline bool AppendQuadInternal(
     scoped_ptr<DrawQuad> draw_quad,
-    gfx::Rect culled_rect,
+    const gfx::Rect& culled_rect,
     QuadList* quad_list,
     const OcclusionTrackerImpl& occlusion_tracker,
     const LayerImpl* layer,
     bool create_debug_border_quads) {
   bool keep_quad = !culled_rect.IsEmpty();
   if (keep_quad)
     draw_quad->visible_rect = culled_rect;
 
   occlusion_tracker.overdraw_metrics()->DidCullForDrawing(
       draw_quad->quadTransform(), draw_quad->rect, culled_rect);
@@ skipping 43 matching lines @@
 
   return AppendQuadInternal(draw_quad.Pass(),
                             culled_rect,
                             quad_list_,
                             occlusion_tracker_,
                             layer_,
                             show_culling_with_debug_border_quads_);
 }
 
 }  // namespace cc