Make ApplicationCache a DOMWindowClient

third_party/WebKit/Source/core/loader/appcache/ApplicationCache.cpp

 /*
  * Copyright (C) 2008, 2009 Apple Inc. All Rights Reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 20 matching lines @@
 #include "core/events/EventListener.h"
 #include "core/frame/Deprecation.h"
 #include "core/frame/HostsUsingFeatures.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/UseCounter.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 
 namespace blink {
 
-ApplicationCache::ApplicationCache(LocalFrame* frame)
-    : ContextLifecycleObserver(frame->document()) {
+ApplicationCache::ApplicationCache(LocalFrame* frame) : DOMWindowClient(frame) {
   ApplicationCacheHost* cacheHost = applicationCacheHost();
   if (cacheHost)
     cacheHost->setApplicationCache(this);
 }
 
 DEFINE_TRACE(ApplicationCache) {
   EventTargetWithInlineData::trace(visitor);
-  ContextLifecycleObserver::trace(visitor);
-}
-
-void ApplicationCache::contextDestroyed() {
-  if (ApplicationCacheHost* cacheHost = applicationCacheHost())

[dcheng, 2017/01/13 09:14:16]

How come it's OK to skip this?

[haraken, 2017/01/13 09:18:21]

cacheHost->setApplicationCache(0) was called just for making
ApplicationCacheHost::dispatchDOMEvent() return early when the context (<-- this
should be window btw) is detached.

After this CL, it is realized by the '!m_domApplicationCache->domWindow()' check
in ApplicationCacheHost::dispatchDOMEvent().

-    cacheHost->setApplicationCache(0);
+  DOMWindowClient::trace(visitor);
 }
 
 ApplicationCacheHost* ApplicationCache::applicationCacheHost() const {
   if (!frame() || !frame()->loader().documentLoader())
     return 0;
   return frame()->loader().documentLoader()->applicationCacheHost();
 }
 
 unsigned short ApplicationCache::status() const {
   recordAPIUseType();
@@ skipping 25 matching lines @@
   ApplicationCacheHost* cacheHost = applicationCacheHost();
   if (cacheHost)
     cacheHost->abort();
 }
 
 const AtomicString& ApplicationCache::interfaceName() const {
   return EventTargetNames::ApplicationCache;
 }
 
 ExecutionContext* ApplicationCache::getExecutionContext() const {
-  if (frame())
-    return frame()->document();
-  return 0;
+  return frame() ? frame()->document() : nullptr;
 }
 
 const AtomicString& ApplicationCache::toEventType(
     ApplicationCacheHost::EventID id) {
   switch (id) {
     case ApplicationCacheHost::kCheckingEvent:
       return EventTypeNames::checking;
     case ApplicationCacheHost::kErrorEvent:
       return EventTypeNames::error;
     case ApplicationCacheHost::kNoupdateEvent:
@@ skipping 27 matching lines @@
   } else {
     Deprecation::countDeprecation(
         document, UseCounter::ApplicationCacheAPIInsecureOrigin);
     HostsUsingFeatures::countAnyWorld(
         *document,
         HostsUsingFeatures::Feature::ApplicationCacheAPIInsecureHost);
   }
 }
 
 }  // namespace blink