Introduce animation frame tasks

third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp

Index: third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp
diff --git a/third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp b/third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp
index 05e09a4ca48b9b9877118a3151132cf402a5f9fd..1fdfc54efb8cee105ecde2fe2434c650d7a155ed 100644
--- a/third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp
+++ b/third_party/WebKit/Source/core/dom/ScriptedAnimationController.cpp
@@ -81,6 +81,13 @@ void ScriptedAnimationController::cancelCallback(CallbackId id) {
   m_callbackCollection.cancelCallback(id);
 }
 
+void ScriptedAnimationController::runTasks() {
+  // TODO(foolip): can running a task append to the task queue?

[Sami, 2016/11/28 15:50:27]

FWIW I'd suggest they get added to the queue for the *next* frame, which is how
rAF works.

[foolip, 2016/12/06 14:01:22]

I have made it so and written tests, can you PTAL?

+  for (std::unique_ptr<WTF::Closure>& task : m_taskQueue)
+    (*task)();
+  m_taskQueue.clear();
+}
+
 void ScriptedAnimationController::dispatchEvents(
     const AtomicString& eventInterfaceFilter) {
   HeapVector<Member<Event>> events;
@@ -144,8 +151,8 @@ bool ScriptedAnimationController::hasScheduledItems() const {
   if (m_suspendCount)
     return false;
 
-  return !m_callbackCollection.isEmpty() || !m_eventQueue.isEmpty() ||
-         !m_mediaQueryListListeners.isEmpty();
+  return !m_callbackCollection.isEmpty() || !m_taskQueue.isEmpty() ||
+         !m_eventQueue.isEmpty() || !m_mediaQueryListListeners.isEmpty();
 }
 
 void ScriptedAnimationController::serviceScriptedAnimations(
@@ -155,11 +162,18 @@ void ScriptedAnimationController::serviceScriptedAnimations(
 
   callMediaQueryListListeners();
   dispatchEvents();
+  runTasks();  // must be after resize event per spec
   executeCallbacks(monotonicTimeNow);
 
   scheduleAnimationIfNeeded();
 }
 
+void ScriptedAnimationController::enqueueTask(
+    std::unique_ptr<WTF::Closure> task) {
+  m_taskQueue.append(std::move(task));
+  scheduleAnimationIfNeeded();
+}
+
 void ScriptedAnimationController::enqueueEvent(Event* event) {
   InspectorInstrumentation::asyncTaskScheduled(
       event->target()->getExecutionContext(), event->type(), event);