Fix the conditions when fullscreen detector listeners are registered

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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/html/MediaCustomControlsFullscreenDetector.h"
 
 #include "core/dom/Fullscreen.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/events/Event.h"
 #include "core/html/HTMLVideoElement.h"
@@ skipping 11 matching lines @@
 
 MediaCustomControlsFullscreenDetector::MediaCustomControlsFullscreenDetector(
     HTMLVideoElement& video)
     : EventListener(CPPEventListenerType),
       m_videoElement(video),
       m_checkViewportIntersectionTimer(
           TaskRunnerHelper::get(TaskType::Unthrottled, &video.document()),
           this,
           &MediaCustomControlsFullscreenDetector::
               onCheckViewportIntersectionTimerFired) {
-  videoElement().addEventListener(EventTypeNames::DOMNodeInsertedIntoDocument,
-                                  this, false);
-  videoElement().addEventListener(EventTypeNames::DOMNodeRemovedFromDocument,
-                                  this, false);
-
-  videoElement().addEventListener(EventTypeNames::loadedmetadata, this, true);
+  if (videoElement().isConnected())
+    attach();
 }
 
 bool MediaCustomControlsFullscreenDetector::operator==(
     const EventListener& other) const {
   return this == &other;
 }
 
 void MediaCustomControlsFullscreenDetector::attach() {
+  videoElement().addEventListener(EventTypeNames::loadedmetadata, this, true);
   videoElement().document().addEventListener(
       EventTypeNames::webkitfullscreenchange, this, true);
   videoElement().document().addEventListener(EventTypeNames::fullscreenchange,
                                              this, true);
 }
 
 void MediaCustomControlsFullscreenDetector::detach() {
+  videoElement().removeEventListener(EventTypeNames::loadedmetadata, this,
+                                     true);
   videoElement().document().removeEventListener(
       EventTypeNames::webkitfullscreenchange, this, true);
   videoElement().document().removeEventListener(
       EventTypeNames::fullscreenchange, this, true);
   m_checkViewportIntersectionTimer.stop();
 
   if (videoElement().webMediaPlayer())
     videoElement().webMediaPlayer()->setIsEffectivelyFullscreen(false);
 }
 
@@ skipping 29 matching lines @@
                kMostlyFillViewportThresholdOfVisibleProportion <
            intersectionRect.height();
   }
   return targetRect.width() * kMostlyFillViewportThresholdOfVisibleProportion <
          intersectionRect.width();
 }
 
 void MediaCustomControlsFullscreenDetector::handleEvent(
     ExecutionContext* context,
     Event* event) {
-  DCHECK(event->type() == EventTypeNames::DOMNodeInsertedIntoDocument ||
-         event->type() == EventTypeNames::DOMNodeRemovedFromDocument ||
-         event->type() == EventTypeNames::loadedmetadata ||
+  DCHECK(event->type() == EventTypeNames::loadedmetadata ||
          event->type() == EventTypeNames::webkitfullscreenchange ||
          event->type() == EventTypeNames::fullscreenchange);
 
-  // Don't early return when the video is inserted into/removed from the
-  // document, as the document might already be in fullscreen.
-  if (event->type() == EventTypeNames::DOMNodeInsertedIntoDocument) {
-    attach();
-  } else if (event->type() == EventTypeNames::DOMNodeRemovedFromDocument) {
-    detach();
-  }
-
   // Video is not loaded yet.
   if (videoElement().getReadyState() < HTMLMediaElement::kHaveMetadata)
     return;
 
   if (!videoElement().isConnected() || !isVideoOrParentFullscreen()) {
     m_checkViewportIntersectionTimer.stop();
 
     if (videoElement().webMediaPlayer())
       videoElement().webMediaPlayer()->setIsEffectivelyFullscreen(false);
 
@@ skipping 35 matching lines @@
 
   return fullscreenElement->contains(&videoElement());
 }
 
 DEFINE_TRACE(MediaCustomControlsFullscreenDetector) {
   EventListener::trace(visitor);
   visitor->trace(m_videoElement);
 }
 
 }  // namespace blink