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..17dbbbb89c51bd6090237c85ccfdd487047abc82 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
@@ -151,10 +151,14 @@ MediaControls::MediaControls(HTMLMediaElement& mediaElement)
                                this,
                                &MediaControls::panelWidthChangedTimerFired),
       m_panelWidth(0),
-      m_keepShowingUntilTimerFires(false) {}
+      m_keepShowingUntilTimerFires(false) {
+        LOG(INFO) << "MediaControls ctor";
+      }
 
 MediaControls* MediaControls::create(HTMLMediaElement& mediaElement,
                                      ShadowRoot& shadowRoot) {
+  // TRACE_EVENT0("Blink", "CreateControls");
+
   MediaControls* controls = new MediaControls(mediaElement);
   controls->setShadowPseudoId(AtomicString("-webkit-media-controls"));
   controls->initializeControls();
@@ -172,6 +176,10 @@ MediaControls* MediaControls::create(HTMLMediaElement& mediaElement,
   return controls;
 }
 
+MediaControls::~MediaControls() {
+  LOG(INFO) << "~MediaControls";
+}
+
 // The media controls DOM structure looks like:
 //
 // MediaControls
@@ -377,6 +385,13 @@ void MediaControls::reset() {
       m_downloadButton->shouldDisplayDownloadButton());
 }
 
+void MediaControls::detach() {
+  m_windowEventListener->stop();
+  m_mediaEventListener->detach();
+  if (m_orientationLockDelegate)
+    m_orientationLockDelegate->detach();
+}
+
 LayoutObject* MediaControls::layoutObjectForTextTrackLayout() {
   return m_panel->layoutObject();
 }
@@ -957,6 +972,7 @@ void MediaControls::hideAllMenus() {
 }
 
 DEFINE_TRACE(MediaControls) {
+  LOG(INFO) << "MediaControls::trace";
   visitor->trace(m_mediaElement);
   visitor->trace(m_panel);
   visitor->trace(m_overlayPlayButton);