cc:: Add RenderingStatsInstrumentation to manage collection of RenderingStats

cc/layer_tree_host.h

Index: cc/layer_tree_host.h
diff --git a/cc/layer_tree_host.h b/cc/layer_tree_host.h
index 9a45ecc8439a6cf9e7eaf85f6df0e9ac4d3545e4..284ee2e5caee5376a9c15800f4a23636911d030b 100644
--- a/cc/layer_tree_host.h
+++ b/cc/layer_tree_host.h
@@ -23,7 +23,6 @@
 #include "cc/output_surface.h"
 #include "cc/proxy.h"
 #include "cc/rate_limiter.h"
-#include "cc/rendering_stats.h"
 #include "cc/scoped_ptr_vector.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
@@ -51,9 +50,11 @@ class LayerTreeHostImplClient;
 class PrioritizedResourceManager;
 class PrioritizedResource;
 class Region;
+class RenderingStatsInstrumentation;
 class ResourceProvider;
 class ResourceUpdateQueue;
 class TopControlsManager;
+struct RenderingStats;
 struct ScrollAndScaleSet;
 
 // Provides information on an Impl's rendering capabilities back to the
@@ -145,6 +146,10 @@ class CC_EXPORT LayerTreeHost : public RateLimiterClient {
 
   void CollectRenderingStats(RenderingStats* stats) const;
 
+  RenderingStatsInstrumentation* rendering_stats_instrumentation() const {
+    return rendering_stats_instrumentation_.get();
+  }
+
   const RendererCapabilities& GetRendererCapabilities() const;
 
   void SetNeedsAnimate();
@@ -243,7 +248,8 @@ class CC_EXPORT LayerTreeHost : public RateLimiterClient {
   bool PaintLayerContents(const LayerList& render_surface_layer_list,
                           ResourceUpdateQueue* quue);
   bool PaintMasksForRenderSurface(Layer* render_surface_layer,
-                                  ResourceUpdateQueue* queue);
+                                  ResourceUpdateQueue* queue,
+                                  RenderingStats* stats);
 
   void UpdateLayers(Layer* root_layer, ResourceUpdateQueue* queue);
   void UpdateHudLayer();
@@ -271,7 +277,7 @@ class CC_EXPORT LayerTreeHost : public RateLimiterClient {
   scoped_ptr<Proxy> proxy_;
 
   int commit_number_;
-  RenderingStats rendering_stats_;
+  scoped_ptr<RenderingStatsInstrumentation> rendering_stats_instrumentation_;
 
   bool renderer_initialized_;
   bool output_surface_lost_;