[cc] Show GPU memory usage and overage below FPS counter

cc/layer_tree_impl.h

 // 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.
 
 #ifndef CC_LAYER_TREE_IMPL_H_
 #define CC_LAYER_TREE_IMPL_H_
 
 #include "base/hash_tables.h"
 #include "cc/layer_impl.h"
 
@@ skipping 10 matching lines @@
 
 namespace cc {
 
 class DebugRectHistory;
 class FrameRateCounter;
 class HeadsUpDisplayLayerImpl;
 class LayerTreeDebugState;
 class LayerTreeHostImpl;
 class LayerTreeImpl;
 class LayerTreeSettings;
+class MemoryHistory;
 class OutputSurface;
 class PaintTimeCounter;
 class Proxy;
 class ResourceProvider;
 class TileManager;
 
 class CC_EXPORT LayerTreeImpl {
  public:
   typedef std::vector<LayerImpl*> LayerList;
 
   static scoped_ptr<LayerTreeImpl> create(LayerTreeHostImpl* layer_tree_host_impl)
   {
     return make_scoped_ptr(new LayerTreeImpl(layer_tree_host_impl));
   }
   virtual ~LayerTreeImpl();
 
   // Methods called by the layer tree that pass-through or access LTHI.
   // ---------------------------------------------------------------------------
   const LayerTreeSettings& settings() const;
   OutputSurface* output_surface() const;
   ResourceProvider* resource_provider() const;
   TileManager* tile_manager() const;
   FrameRateCounter* frame_rate_counter() const;
   PaintTimeCounter* paint_time_counter() const;
+  MemoryHistory* memory_history() const;
   bool IsActiveTree() const;
   bool IsPendingTree() const;
   bool IsRecycleTree() const;
   LayerImpl* FindActiveTreeLayerById(int id);
   LayerImpl* FindPendingTreeLayerById(int id);
   int MaxTextureSize() const;
   bool PinchGestureActive() const;
   base::TimeTicks CurrentFrameTime() const;
 
   // Tree specific methods exposed to layer-impl tree.
@@ skipping 147 matching lines @@
   // In impl-side painting mode, this is true when the tree may contain
   // structural differences relative to the active tree.
   bool needs_full_tree_sync_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }
 
 #endif  // CC_LAYER_TREE_IMPL_H_