Add a way to schedule generic per-frame events through Document.

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 893 matching lines @@
 
     virtual bool isContextThread() const OVERRIDE FINAL;
     virtual bool isJSExecutionForbidden() const OVERRIDE FINAL { return false; }
 
     bool containsValidityStyleRules() const { return m_containsValidityStyleRules; }
     void setContainsValidityStyleRules() { m_containsValidityStyleRules = true; }
 
     void enqueueResizeEvent();
     void enqueueScrollEventForNode(Node*);
     void enqueueAnimationFrameEvent(PassRefPtrWillBeRawPtr<Event>);
+    // Only one event for a target/event type combination will be dispatched per frame.
+    void enqueueUniqueAnimationFrameEvent(PassRefPtrWillBeRawPtr<Event>);
     void enqueueMediaQueryChangeListeners(WillBeHeapVector<RefPtrWillBeMember<MediaQueryListListener> >&);
 
     bool hasFullscreenElementStack() const { return m_hasFullscreenElementStack; }
     void setHasFullscreenElementStack() { m_hasFullscreenElementStack = true; }
 
     void exitPointerLock();
     Element* pointerLockElement() const;
 
     // Used to allow element that loads data without going through a FrameLoader to delay the 'load' event.
     void incrementLoadEventDelayCount() { ++m_loadEventDelayCount; }
@@ skipping 506 matching lines @@
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h