Add EventHandlerRegistry

Source/core/testing/Internals.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 123 matching lines @@
     [RaisesException] ClientRect bestZoomableAreaForTouchPoint(long x, long y, long width, long height, Document document);
 
     [RaisesException] long lastSpellCheckRequestSequence(Document document);
     [RaisesException] long lastSpellCheckProcessedSequence(Document document);
 
     sequence<DOMString> userPreferredLanguages();
     void setUserPreferredLanguages(sequence<DOMString> languages);
 
     [RaisesException] unsigned long activeDOMObjectCount(Document document);
     [RaisesException] unsigned long wheelEventHandlerCount(Document document);
+    [RaisesException] unsigned long scrollEventHandlerCount(Document document);
     [RaisesException] unsigned long touchEventHandlerCount(Document document);
     [RaisesException] LayerRectList touchEventTargetLayerRects(Document document);
 
 
     [RaisesException] NodeList nodesFromRect(Document document, long x, long y,
         unsigned long topPadding, unsigned long rightPadding, unsigned long bottomPadding, unsigned long leftPadding,
         boolean ignoreClipping, boolean allowShadowContent, boolean allowChildFrameContent);
 
     void emitInspectorDidBeginFrame(optional long frameId);
     void emitInspectorDidCancelFrame();
@@ skipping 128 matching lines @@
     [CallWith=ExecutionContext] Promise createPromise();
     [CallWith=ExecutionContext] Promise createResolvedPromise(any value);
     [CallWith=ExecutionContext] Promise createRejectedPromise(any reason);
     [CallWith=ExecutionContext] Promise addOneToPromise(Promise promise);
 
     void startSpeechInput(Element element);
     void setValueForUser(Element element, DOMString value);
 
     DOMString textSurroundingNode(Node node, long x, long y, unsigned long maxLength);
 };