compositor-worker: Initialize CW machinery plumbing to compositor and fire CW rAF callbacks.

third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp

Index: third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp
diff --git a/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp b/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp
index 38f958c7f366a1c3106d8af1cb3f3323c277d9be..d660f90cc768e4e0e1d986858c61e332b17bc914 100644
--- a/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp
+++ b/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp
@@ -24,8 +24,10 @@ CompositorWorkerGlobalScope* CompositorWorkerGlobalScope::create(CompositorWorke
 
 CompositorWorkerGlobalScope::CompositorWorkerGlobalScope(const KURL& url, const String& userAgent, CompositorWorkerThread* thread, double timeOrigin, PassOwnPtr<SecurityOrigin::PrivilegeData> starterOriginPrivilegeData, WorkerClients* workerClients)
     : WorkerGlobalScope(url, userAgent, thread, timeOrigin, std::move(starterOriginPrivilegeData), workerClients)
+    , m_executingAnimationFrameCallbacks(false)
     , m_callbackCollection(this)
 {
+    CompositorProxyClient::from(clients())->setGlobalScope(this);
 }
 
 CompositorWorkerGlobalScope::~CompositorWorkerGlobalScope()
@@ -54,6 +56,9 @@ void CompositorWorkerGlobalScope::postMessage(ExecutionContext* executionContext
 
 int CompositorWorkerGlobalScope::requestAnimationFrame(FrameRequestCallback* callback)
 {
+    const bool shouldSignal = !m_executingAnimationFrameCallbacks && m_callbackCollection.isEmpty();
+    if (shouldSignal)
+        CompositorProxyClient::from(clients())->requestAnimationFrame();
     return m_callbackCollection.registerCallback(callback);
 }
 
@@ -62,9 +67,11 @@ void CompositorWorkerGlobalScope::cancelAnimationFrame(int id)
     m_callbackCollection.cancelCallback(id);
 }
 
-void CompositorWorkerGlobalScope::executeAnimationFrameCallbacks(double highResTimeNow)
+bool CompositorWorkerGlobalScope::executeAnimationFrameCallbacks(double highResTimeMs)
 {
-    m_callbackCollection.executeCallbacks(highResTimeNow, highResTimeNow);
+    TemporaryChange<bool> temporaryChange(m_executingAnimationFrameCallbacks, true);
+    m_callbackCollection.executeCallbacks(highResTimeMs, highResTimeMs);
+    return !m_callbackCollection.isEmpty();
 }
 
 CompositorWorkerThread* CompositorWorkerGlobalScope::thread() const