[oilpan] Make the oilpan branch build on Mac.

Source/core/dom/DocumentEventQueue.cpp

 /*
  * Copyright (C) 2010 Google 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 140 matching lines @@
         if (!event)
             break;
         dispatchEvent(event.get());
     }
 }
 
 void DocumentEventQueue::dispatchEvent(PassRefPtr<Event> event)
 {
     EventTarget* eventTarget = event->target();
     if (eventTarget->toDOMWindow())
-        eventTarget->toDOMWindow()->dispatchEvent(event, 0);
+        eventTarget->toDOMWindow()->dispatchEvent(event, Handle<Document>(nullptr));
     else
         eventTarget->dispatchEvent(event);
 }
 
 }