Make DOMWindowProperty a thin wrapper of ContextLifecycleObserver

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 455 matching lines @@
 
 LocalDOMWindow* LocalDOMWindow::toLocalDOMWindow() {
   return this;
 }
 
 MediaQueryList* LocalDOMWindow::matchMedia(const String& media) {
   return document() ? document()->mediaQueryMatcher().matchMedia(media)
                     : nullptr;
 }
 
-void LocalDOMWindow::frameDestroyed() {
-  for (const auto& domWindowProperty : m_properties)
-    domWindowProperty->frameDestroyed();
-
+void LocalDOMWindow::contextDestroyed() {
   resetLocation();
-  m_properties.clear();
   removeAllEventListeners();
   m_frame = nullptr;
 }
 
-void LocalDOMWindow::registerProperty(DOMWindowProperty* property) {
-  m_properties.add(property);
-}
-
-void LocalDOMWindow::unregisterProperty(DOMWindowProperty* property) {
-  m_properties.remove(property);

[dcheng, 2016/12/12 06:50:50]

Oh wow... this hasn't been called in some time.

[haraken, 2016/12/12 06:54:28]

It would be okay because m_properties is a hash set of weak members. We need to
call unregisterProperty only when we want to promptly remove the entry from the
hash set.

[sof, 2016/12/12 13:00:50]

Yes, I wouldn't be too surprised if there are a couple of unused unregistration
methods like that still around in the codebase.

-}
-
 void LocalDOMWindow::registerEventListenerObserver(
     EventListenerObserver* eventListenerObserver) {
   m_eventListenerObservers.add(eventListenerObserver);
 }
 
 void LocalDOMWindow::reset() {
   DCHECK(document());
   // Since |Document| class has multiple |LifecycleNotifier| as base class,
   // we need to have |static_cast<ExecutionContext>| here.
   static_cast<ExecutionContext*>(document())->notifyContextDestroyed();
-  frameDestroyed();
+  contextDestroyed();
 
   m_screen = nullptr;
   m_history = nullptr;
   m_locationbar = nullptr;
   m_menubar = nullptr;
   m_personalbar = nullptr;
   m_scrollbars = nullptr;
   m_statusbar = nullptr;
   m_toolbar = nullptr;
   m_navigator = nullptr;
@@ skipping 1022 matching lines @@
 
   WindowFeatures features(windowFeaturesString);
   DOMWindow* newWindow = createWindow(urlString, frameName, features,
                                       *callingWindow, *firstFrame, *frame());
   return features.noopener ? nullptr : newWindow;
 }
 
 DEFINE_TRACE(LocalDOMWindow) {
   visitor->trace(m_frame);
   visitor->trace(m_document);
-  visitor->trace(m_properties);
   visitor->trace(m_screen);
   visitor->trace(m_history);
   visitor->trace(m_locationbar);
   visitor->trace(m_menubar);
   visitor->trace(m_personalbar);
   visitor->trace(m_scrollbars);
   visitor->trace(m_statusbar);
   visitor->trace(m_toolbar);
   visitor->trace(m_navigator);
   visitor->trace(m_media);
   visitor->trace(m_customElements);
   visitor->trace(m_applicationCache);
   visitor->trace(m_eventQueue);
   visitor->trace(m_postMessageTimers);
   visitor->trace(m_visualViewport);
   visitor->trace(m_eventListenerObservers);
   DOMWindow::trace(visitor);
   Supplementable<LocalDOMWindow>::trace(visitor);
 }
 
 LocalFrame* LocalDOMWindow::frame() const {
   // If the LocalDOMWindow still has a frame reference, that frame must point
   // back to this LocalDOMWindow: otherwise, it's easy to get into a situation
   // where script execution leaks between different LocalDOMWindows.
   SECURITY_DCHECK(!m_frame || m_frame->domWindow() == this);
   return m_frame;
 }
 
 }  // namespace blink