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

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

Index: third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
index 3d5cff44270ef8cc0f3189a9601eb66169b10e9c..087b1013c313014963936a4221c8eedf8a6e6212 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
@@ -688,6 +688,27 @@ bool MediaControls::containsRelatedTarget(Event* event) {
   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