Make DOMWindowProperty a thin wrapper of ContextLifecycleObserver

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

Index: third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
index c30f6aa96631fb5be970635f4928b60ba60e7278..1175d074df752344557194c242aa803f72960037 100644
--- a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
@@ -473,24 +473,12 @@ MediaQueryList* LocalDOMWindow::matchMedia(const String& 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);
@@ -501,7 +489,7 @@ void LocalDOMWindow::reset() {
   // 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;
@@ -1544,7 +1532,6 @@ DOMWindow* LocalDOMWindow::open(const String& urlString,
 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);