cc: Report only on active tiles in tracing.

cc/layers/layer_impl.h

 // 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.
 
 #ifndef CC_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 
@@ skipping 505 matching lines @@
     return scroll_clip_layer_ ? scroll_clip_layer_->bounds().height() : 0;
   }
 
   gfx::Rect LayerRectToContentRect(const gfx::RectF& layer_rect) const;
 
   virtual skia::RefPtr<SkPicture> GetPicture();
 
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
   virtual void PushPropertiesTo(LayerImpl* layer);
 
+  virtual void GetAllTilesForTracing(std::set<const Tile*>* tiles) const;
   virtual void AsValueInto(base::debug::TracedValue* dict) const;
 
   virtual size_t GPUMemoryUsageInBytes() const;
 
   void SetNeedsPushProperties();
   void AddDependentNeedsPushProperties();
   void RemoveDependentNeedsPushProperties();
   bool parent_should_know_need_push_properties() const {
     return needs_push_properties() || descendant_needs_push_properties();
   }
@@ skipping 167 matching lines @@
   DrawProperties<LayerImpl> draw_properties_;
 
   scoped_refptr<base::debug::ConvertableToTraceFormat> debug_info_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_