rAF: Introduce FrameRequestCallbackCollection for managing rAF callbacks.

Source/core/dom/ScriptedAnimationController.h

Index: Source/core/dom/ScriptedAnimationController.h
diff --git a/Source/core/dom/ScriptedAnimationController.h b/Source/core/dom/ScriptedAnimationController.h
index a833730103c899a446ff1c7f496cf096768a3ede..c739217648e3e1355a8b32ef33e0556046cb1514 100644
--- a/Source/core/dom/ScriptedAnimationController.h
+++ b/Source/core/dom/ScriptedAnimationController.h
@@ -26,6 +26,7 @@
 #ifndef ScriptedAnimationController_h
 #define ScriptedAnimationController_h
 
+#include "core/dom/RequestAnimationFrameCallbackCollection.h"
 #include "platform/heap/Handle.h"
 #include "wtf/ListHashSet.h"
 #include "wtf/RefCounted.h"
@@ -76,12 +77,8 @@ private:
     void executeCallbacks(double monotonicTimeNow);
     void callMediaQueryListListeners();
 
-    typedef PersistentHeapVectorWillBeHeapVector<Member<RequestAnimationFrameCallback>> CallbackList;
-    CallbackList m_callbacks;
-    CallbackList m_callbacksToInvoke; // only non-empty while inside executeCallbacks
-
     RawPtrWillBeMember<Document> m_document;
-    CallbackId m_nextCallbackId;
+    RequestAnimationFrameCallbackCollection m_callbackCollection;
     int m_suspendCount;
     WillBeHeapVector<RefPtrWillBeMember<Event>> m_eventQueue;
     WillBeHeapListHashSet<std::pair<RawPtrWillBeMember<const EventTarget>, const StringImpl*>> m_perFrameEvents;