Provide a vsync notification to the renderer

cc/thread_proxy.cc

Index: cc/thread_proxy.cc
diff --git a/cc/thread_proxy.cc b/cc/thread_proxy.cc
index adb9d016d020f8acb2c046493c0daf03fb706fc4..cb8e49baebc77a532169e3fb89c0db7a8baf5629 100644
--- a/cc/thread_proxy.cc
+++ b/cc/thread_proxy.cc
@@ -59,6 +59,8 @@ ThreadProxy::ThreadProxy(LayerTreeHost* layerTreeHost, scoped_ptr<Thread> implTh
     , m_nextFrameIsNewlyCommittedFrameOnImplThread(false)
     , m_renderVSyncEnabled(layerTreeHost->settings().renderVSyncEnabled)
     , m_insideDraw(false)
+    , m_renderVSyncNotificationEnabled(layerTreeHost->settings().renderVSyncNotificationEnabled)
+    , m_vsyncClient(0)
     , m_totalCommitCount(0)
     , m_deferCommits(false)
     , m_renewTreePriorityOnImplThreadPending(false)
@@ -332,6 +334,14 @@ void ThreadProxy::onVSyncParametersChanged(base::TimeTicks timebase, base::TimeD
     m_schedulerOnImplThread->setTimebaseAndInterval(timebase, interval);
 }
 
+void ThreadProxy::didVSync(base::TimeTicks frameTime)
+{
+    DCHECK(isImplThread());
+    TRACE_EVENT0("cc", "ThreadProxy::didVSync");
+    if (m_vsyncClient)
+        m_vsyncClient->DidVSync(frameTime);
+}
+
 void ThreadProxy::onCanDrawStateChanged(bool canDraw)
 {
     DCHECK(isImplThread());
@@ -991,9 +1001,12 @@ void ThreadProxy::initializeImplOnImplThread(CompletionEvent* completion, InputH
     m_layerTreeHostImpl = m_layerTreeHost->createLayerTreeHostImpl(this);
     const base::TimeDelta displayRefreshInterval = base::TimeDelta::FromMicroseconds(base::Time::kMicrosecondsPerSecond / 60);
     scoped_ptr<FrameRateController> frameRateController;
-    if (m_renderVSyncEnabled)
-        frameRateController.reset(new FrameRateController(DelayBasedTimeSource::create(displayRefreshInterval, Proxy::implThread())));
-    else
+    if (m_renderVSyncEnabled) {
+        if (m_renderVSyncNotificationEnabled)
+            frameRateController.reset(new FrameRateController(VSyncTimeSource::create(this)));
+        else
+            frameRateController.reset(new FrameRateController(DelayBasedTimeSource::create(displayRefreshInterval, Proxy::implThread())));
+    } else
         frameRateController.reset(new FrameRateController(Proxy::implThread()));
     SchedulerSettings schedulerSettings;
     schedulerSettings.implSidePainting = m_layerTreeHost->settings().implSidePainting;
@@ -1043,6 +1056,7 @@ void ThreadProxy::layerTreeHostClosedOnImplThread(CompletionEvent* completion)
     m_layerTreeHost->deleteContentsTexturesOnImplThread(m_layerTreeHostImpl->resourceProvider());
     m_inputHandlerOnImplThread.reset();
     m_layerTreeHostImpl.reset();
+    m_vsyncClient = 0;
     m_schedulerOnImplThread.reset();
     m_weakFactoryOnImplThread.InvalidateWeakPtrs();
     completion->signal();
@@ -1079,6 +1093,13 @@ void ThreadProxy::renderingStatsOnImplThread(CompletionEvent* completion, Render
     completion->signal();
 }
 
+void ThreadProxy::RequestVSyncNotification(VSyncClient* client)
+{
+    DCHECK(isImplThread());
+    m_vsyncClient = client;
+    m_layerTreeHostImpl->enableVSyncNotification(client);
+}
+
 ThreadProxy::BeginFrameAndCommitState::BeginFrameAndCommitState()
     : memoryAllocationLimitBytes(0)
 {