NOT READY FOR REVIEW - switch to a subscriber model for rendering stats

cc/single_thread_proxy.cc

Index: cc/single_thread_proxy.cc
diff --git a/cc/single_thread_proxy.cc b/cc/single_thread_proxy.cc
index 6c63c3d9d4e5a4153d412ceb808eb216ce5292d0..93a26f2279ed7bd4225b4c8598da4d3faa2f1945 100644
--- a/cc/single_thread_proxy.cc
+++ b/cc/single_thread_proxy.cc
@@ -6,6 +6,10 @@
 
 #include "cc/single_thread_proxy.h"
 
+#include "cc/rendering_stats_subscriber.h"
+#include <wtf/CurrentTime.h>
+
+using namespace WTF;
 #include "base/debug/trace_event.h"
 #include "cc/draw_quad.h"
 #include "cc/graphics_context.h"
@@ -154,6 +158,20 @@ void SingleThreadProxy::renderingStats(RenderingStats* stats)
     m_layerTreeHostImpl->renderingStats(stats);
 }
 
+void SingleThreadProxy::startRecordingRenderingStats()
+{
+    // This subscriber will collect total commit time and total commit count.
+    m_renderingStatsSubscriber = RenderingStatsSubscriber::create();
+    m_layerTreeHostImpl->startRecordingRenderingStats();
+}
+
+void SingleThreadProxy::stopRecordingRenderingStats(RenderingStats* stats)
+{
+    // TODO(vollick): populate stats based on the subscriber here.
+    m_renderingStatsSubscriber.reset();
+    m_layerTreeHostImpl->stopRecordingRenderingStats(stats);
+}
+
 const RendererCapabilities& SingleThreadProxy::rendererCapabilities() const
 {
     DCHECK(m_rendererInitialized);