Media: fix memory leak because of the document holding on an EventListener.

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 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
@@ skipping 663 matching lines @@
 
 bool MediaControls::containsRelatedTarget(Event* event) {
   if (!event->isMouseEvent())
     return false;
   EventTarget* relatedTarget = toMouseEvent(event)->relatedTarget();
   if (!relatedTarget)
     return false;
   return contains(relatedTarget->toNode());
 }
 
+void MediaControls::onInsertedIntoDocument() {
+  // TODO(mlamouri): we should show the controls instead of having
+  // HTMLMediaElement do it.
+
+  // m_windowEventListener doesn't need to be re-attached as it's only needed
+  // when a menu is visible.
+  m_mediaEventListener->attach();
+  if (m_orientationLockDelegate)
+    m_orientationLockDelegate->attach();
+}
+
+void MediaControls::onRemovedFromDocument() {
+  // TODO(mlamouri): we hide show the controls instead of having
+  // HTMLMediaElement do it.
+
+  m_windowEventListener->stop();
+  m_mediaEventListener->detach();
+  if (m_orientationLockDelegate)
+    m_orientationLockDelegate->detach();
+}
+
 void MediaControls::onVolumeChange() {
   m_muteButton->updateDisplayType();
   m_volumeSlider->setVolume(mediaElement().muted() ? 0
                                                    : mediaElement().volume());
 
   // Update visibility of volume controls.
   // TODO(mlamouri): it should not be part of the volumechange handling because
   // it is using audio availability as input.
   BatchedControlUpdate batch(this);
   m_volumeSlider->setIsWanted(mediaElement().hasAudio() &&
@@ skipping 275 matching lines @@
   visitor->trace(m_overflowList);
   visitor->trace(m_castButton);
   visitor->trace(m_overlayCastButton);
   visitor->trace(m_mediaEventListener);
   visitor->trace(m_windowEventListener);
   visitor->trace(m_orientationLockDelegate);
   HTMLDivElement::trace(visitor);
 }
 
 }  // namespace blink