Oilpan: fix MediaController crashes after r176358.

Source/core/html/MediaController.cpp

 /*
  * Copyright (C) 2011 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/html/MediaController.h"
 
 #include "bindings/v8/ExceptionMessages.h"
 #include "bindings/v8/ExceptionState.h"
 #include "bindings/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/ExecutionContext.h"
 #include "core/events/Event.h"
 #include "core/events/GenericEventQueue.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/TimeRanges.h"
 #include "platform/Clock.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/text/AtomicString.h"
 
 namespace WebCore {
@@ skipping 569 matching lines @@
 
 void MediaController::trace(Visitor* visitor)
 {
     visitor->trace(m_mediaElements);
     visitor->trace(m_pendingEventsQueue);
     visitor->trace(m_executionContext);
     EventTargetWithInlineData::trace(visitor);
 }
 
 }