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

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index b20a17edb06b0a4bee5031030d34d2891a6fd04a..c82535fd716627aa3d8de1467f109f37478fd28a 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -100,7 +100,7 @@
 #include "wtf/text/CString.h"
 
 #ifndef BLINK_MEDIA_LOG
-#define BLINK_MEDIA_LOG DVLOG(3)
+#define BLINK_MEDIA_LOG LOG(INFO)
 #endif
 
 #ifndef LOG_MEDIA_EVENTS
@@ -496,6 +496,8 @@ HTMLMediaElement::~HTMLMediaElement() {
 void HTMLMediaElement::dispose() {
   closeMediaSource();
 
+  LOG(INFO) << "HTMLMediaElement::dispose";
+
   // Destroying the player may cause a resource load to be canceled,
   // which could result in LocalDOMWindow::dispatchWindowLoadEvent() being
   // called via ResourceFetch::didLoadResource(), then
@@ -654,6 +656,7 @@ Node::InsertionNotificationRequest HTMLMediaElement::insertedInto(
 }
 
 void HTMLMediaElement::didNotifySubtreeInsertionsToDocument() {
+  BLINK_MEDIA_LOG << "didNotifySubtreeInsertionsToDocument()";
   updateControlsVisibility();
 }
 
@@ -664,6 +667,8 @@ void HTMLMediaElement::removedFrom(ContainerNode* insertionPoint) {
   HTMLElement::removedFrom(insertionPoint);
   if (insertionPoint->inActiveDocument()) {
     updateControlsVisibility();
+    m_mediaControls->detach();
+    m_mediaControls = nullptr;
     if (m_networkState > kNetworkEmpty)
       pauseInternal();
   }
@@ -3804,6 +3809,7 @@ bool HTMLMediaElement::isInteractiveContent() const {
 }
 
 DEFINE_TRACE(HTMLMediaElement) {
+  LOG(INFO) << "HTMLMediaElement::trace";
   visitor->trace(m_playedTimeRanges);
   visitor->trace(m_asyncEventQueue);
   visitor->trace(m_error);