InitEvent should not do anything if dispatch flag is set.

third_party/WebKit/Source/core/events/KeyboardEvent.cpp

 /**
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 95 matching lines @@
     initLocationModifiers(location);
 }
 
 KeyboardEvent::~KeyboardEvent()
 {
 }
 
 void KeyboardEvent::initKeyboardEvent(ScriptState* scriptState, const AtomicString& type, bool canBubble, bool cancelable, AbstractView* view,
     const String& keyIdentifier, unsigned location, bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
 {
-    if (dispatched())
+    if (isBeingDispatched())
         return;
 
     if (scriptState->world().isIsolatedWorld())
         UIEventWithKeyState::didCreateEventInIsolatedWorld(ctrlKey, altKey, shiftKey, metaKey);
 
     initUIEvent(type, canBubble, cancelable, view, 0);
 
     m_keyIdentifier = keyIdentifier;
     m_location = location;
     initModifiers(ctrlKey, altKey, shiftKey, metaKey);
@@ skipping 64 matching lines @@
         break;
     }
 }
 
 DEFINE_TRACE(KeyboardEvent)
 {
     UIEventWithKeyState::trace(visitor);
 }
 
 } // namespace blink