cc:: Add RenderingStatsInstrumentation to manage collection of RenderingStats

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index 71c46522f1af246ddf5e5cb1bf19457daa85a0bd..da2046a390bc9e73faaac5d20cfc0800bfba14eb 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -171,12 +171,6 @@ bool SingleThreadProxy::RecreateOutputSurface() {
   return initialized;
 }
 
-void SingleThreadProxy::CollectRenderingStats(RenderingStats* stats) {
-  stats->totalCommitTime = total_commit_time_;
-  stats->totalCommitCount = total_commit_count_;
-  layer_tree_host_impl_->CollectRenderingStats(stats);
-}
-
 const RendererCapabilities& SingleThreadProxy::GetRendererCapabilities() const {
   DCHECK(renderer_initialized_);
   // Note: this gets called during the commit by the "impl" thread.
@@ -195,7 +189,10 @@ void SingleThreadProxy::DoCommit(scoped_ptr<ResourceUpdateQueue> queue) {
     DebugScopedSetMainThreadBlocked mainThreadBlocked(this);
     DebugScopedSetImplThread impl(this);
 
-    base::TimeTicks startTime = base::TimeTicks::HighResNow();
+    RenderingStatsInstrumentation* stats_instrumentation =
+        layer_tree_host_->rendering_stats_instrumentation();
+    base::TimeTicks startTime = stats_instrumentation->StartRecording();
+
     layer_tree_host_impl_->BeginCommit();
 
     layer_tree_host_->contents_texture_manager()->
@@ -222,9 +219,8 @@ void SingleThreadProxy::DoCommit(scoped_ptr<ResourceUpdateQueue> queue) {
     DCHECK(!scrollInfo->scrolls.size());
 #endif
 
-    base::TimeTicks endTime = base::TimeTicks::HighResNow();
-    total_commit_time_ += endTime - startTime;
-    total_commit_count_++;
+    base::TimeDelta duration = stats_instrumentation->EndRecording(startTime);
+    stats_instrumentation->AddCommit(duration);
   }
   layer_tree_host_->CommitComplete();
   next_frame_is_newly_committed_frame_ = true;