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

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

Index: third_party/WebKit/Source/core/html/shadow/MediaControlsOrientationLockDelegate.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlsOrientationLockDelegate.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControlsOrientationLockDelegate.cpp
index 624bb9d699665c15f24c9a04de2425fe35b4b8a1..187db61dd904b784347e8b686212c1cc918411c2 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlsOrientationLockDelegate.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlsOrientationLockDelegate.cpp
@@ -75,6 +75,10 @@ bool MediaControlsOrientationLockDelegate::operator==(
   return this == &other;
 }
 
+void MediaControlsOrientationLockDelegate::detach() {
+  document().removeEventListener(EventTypeNames::fullscreenchange, this, true);

[Zhiqiang Zhang (Slow), 2017/03/01 16:22:36]

Should we also remove the listeners from the video element? In case the page
adds/removes the element to/from the page multiple times, we are creating many
MediaControl objects and this will prevent the
MediaControlsOrientationLockDelegate objects to be gc-ed.

[mlamouri (slow - plz ping), 2017/03/01 20:22:33]

Good point :) Though, the approach the first iteration was taking didn't work so
I had to change. 

+}
+
 void MediaControlsOrientationLockDelegate::maybeLockOrientation() {
   DCHECK(m_state != State::MaybeLockedFullscreen);