Fix the conditions when fullscreen detector listeners are registered

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

Index: third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp b/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
index 90a86f6e9897604811faebcbd56eb3150fb0f959..d5bf83fd45bfdd6f11d67ef53d1000e5fb7af0bf 100644
--- a/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
@@ -79,6 +79,21 @@ DEFINE_TRACE(HTMLVideoElement) {
   HTMLMediaElement::trace(visitor);
 }
 
+Node::InsertionNotificationRequest HTMLVideoElement::insertedInto(
+    ContainerNode* insertionPoint) {
+  if (insertionPoint->isConnected() && m_customControlsFullscreenDetector)
+    m_customControlsFullscreenDetector->attach();
+
+  return HTMLMediaElement::insertedInto(insertionPoint);
+}
+
+void HTMLVideoElement::removedFrom(ContainerNode* insertionPoint) {
+  HTMLMediaElement::removedFrom(insertionPoint);
+
+  if (insertionPoint->inActiveDocument() && m_customControlsFullscreenDetector)

[mlamouri (slow - plz ping), 2017/03/20 17:05:25]

OOC, why are you adding this? I did not really understood why HTMLMediaELement
had this check. MediaControls doesn't have it.

[Zhiqiang Zhang (Slow), 2017/03/20 17:14:22]

The check is to see if the node was connected to an active document before
removing. I think we can remove it as removing unregistered listeners is no-op.

+    m_customControlsFullscreenDetector->detach();
+}
+
 void HTMLVideoElement::contextDestroyed(ExecutionContext* context) {
   if (m_customControlsFullscreenDetector)
     m_customControlsFullscreenDetector->contextDestroyed();