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

cc/thread_proxy.cc

Index: cc/thread_proxy.cc
diff --git a/cc/thread_proxy.cc b/cc/thread_proxy.cc
index 688d1e3c5c4b6790a31161db25c2dbdd5da53a79..656c8bdfe4402200ac0936639e789f25d009899f 100644
--- a/cc/thread_proxy.cc
+++ b/cc/thread_proxy.cc
@@ -14,6 +14,7 @@
 #include "cc/graphics_context.h"
 #include "cc/input_handler.h"
 #include "cc/layer_tree_host.h"
+#include "cc/rendering_stats_subscriber.h"
 #include "cc/scheduler.h"
 #include "cc/scoped_thread_proxy.h"
 #include <public/WebSharedGraphicsContext3D.h>
@@ -258,6 +259,34 @@ void ThreadProxy::renderingStats(RenderingStats* stats)
     completion.wait();
 }
 
+void ThreadProxy::startRecordingRenderingStats()
+{
+    DCHECK(isMainThread());
+
+    DebugScopedSetMainThreadBlocked mainThreadBlocked;
+    CompletionEvent completion;
+    Proxy::implThread()->postTask(base::Bind(&ThreadProxy::startRecordingRenderingStatsOnImplThread,
+                                             base::Unretained(this), &completion));
+
+    // This subscriber will collect total commit time and total commit count.
+    m_renderingStatsSubscriber = RenderingStatsSubscriber::create();
+    completion.wait();
+}
+
+void ThreadProxy::stopRecordingRenderingStats(RenderingStats* stats)
+{
+    DCHECK(isMainThread());
+
+    // TODO(vollick) populate stats based on subscriber here.
+    m_renderingStatsSubscriber.reset();
+
+    DebugScopedSetMainThreadBlocked mainThreadBlocked;
+    CompletionEvent completion;
+    Proxy::implThread()->postTask(base::Bind(&ThreadProxy::stopRecordingRenderingStatsOnImplThread,
+                                             base::Unretained(this), &completion, stats));
+    completion.wait();
+}
+
 const RendererCapabilities& ThreadProxy::rendererCapabilities() const
 {
     DCHECK(m_rendererInitialized);
@@ -981,6 +1010,20 @@ void ThreadProxy::renderingStatsOnImplThread(CompletionEvent* completion, Render
     completion->signal();
 }
 
+void ThreadProxy::startRecordingRenderingStatsOnImplThread(CompletionEvent* completion)
+{
+    DCHECK(isImplThread());
+    m_layerTreeHostImpl->startRecordingRenderingStats();
+    completion->signal();
+}
+
+void ThreadProxy::stopRecordingRenderingStatsOnImplThread(CompletionEvent* completion, RenderingStats* stats)
+{
+    DCHECK(isImplThread());
+    m_layerTreeHostImpl->stopRecordingRenderingStats(stats);
+    completion->signal();
+}
+
 ThreadProxy::BeginFrameAndCommitState::BeginFrameAndCommitState()
 {
 }