rAF: Introduce FrameRequestCallbackCollection for managing rAF callbacks.

Source/core/frame/RemoteDOMWindow.h

Index: Source/core/frame/RemoteDOMWindow.h
diff --git a/Source/core/frame/RemoteDOMWindow.h b/Source/core/frame/RemoteDOMWindow.h
index c15d710fcff48c4414b5bad27a3ac9b757702231..55281a3ce4c8b4d4cb8b731ef90f21cd892c4ee8 100644
--- a/Source/core/frame/RemoteDOMWindow.h
+++ b/Source/core/frame/RemoteDOMWindow.h
@@ -77,8 +77,8 @@ public:
     PassRefPtrWillBeRawPtr<MediaQueryList> matchMedia(const String&) override;
     PassRefPtrWillBeRawPtr<CSSStyleDeclaration> getComputedStyle(Element*, const String& pseudoElt) const override;
     PassRefPtrWillBeRawPtr<CSSRuleList> getMatchedCSSRules(Element*, const String& pseudoElt) const override;
-    int requestAnimationFrame(RequestAnimationFrameCallback*) override;
-    int webkitRequestAnimationFrame(RequestAnimationFrameCallback*) override;
+    int requestAnimationFrame(FrameRequestCallback*) override;
+    int webkitRequestAnimationFrame(FrameRequestCallback*) override;
     void cancelAnimationFrame(int id) override;
     String sanitizedCrossDomainAccessErrorMessage(LocalDOMWindow* callingWindow) override;
     String crossDomainAccessErrorMessage(LocalDOMWindow* callingWindow) override;