Oilpan: Remove a visitor parameter from isHeapObjectAlive

Source/modules/mediasource/MediaSource.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 251 matching lines @@
 {
     return ActiveDOMObject::executionContext();
 }
 
 void MediaSource::clearWeakMembers(Visitor* visitor)
 {
 #if ENABLE(OILPAN)
     // Oilpan: If the MediaSource survived, but its attached media
     // element did not, signal the element that it can safely
     // notify its MediaSource during finalization by calling close().
-    if (m_attachedElement && !visitor->isHeapObjectAlive(m_attachedElement)) {
+    if (m_attachedElement && !Heap::isHeapObjectAlive(m_attachedElement)) {
         m_attachedElement->setCloseMediaSourceWhenFinalizing();
         m_attachedElement.clear();
     }
 #endif
 }
 
 DEFINE_TRACE(MediaSource)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_asyncEventQueue);
@@ skipping 330 matching lines @@
 
     m_asyncEventQueue->enqueueEvent(event.release());
 }
 
 URLRegistry& MediaSource::registry() const
 {
     return MediaSourceRegistry::registry();
 }
 
 } // namespace blink