Revert of Explicit notification and removal of lifecycle observers.

Source/core/dom/ExecutionContext.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2012 Google 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
@@ skipping 78 matching lines @@
     m_activeDOMObjectsAreSuspended = false;
     lifecycleNotifier().notifyResumingActiveDOMObjects();
 }
 
 void ExecutionContext::stopActiveDOMObjects()
 {
     m_activeDOMObjectsAreStopped = true;
     lifecycleNotifier().notifyStoppingActiveDOMObjects();
 }
 
-void ExecutionContext::removeAllLifecycleObservers()
-{
-    lifecycleNotifier().removeAndNotifyAllObservers();
-}
-
 unsigned ExecutionContext::activeDOMObjectCount()
 {
     return lifecycleNotifier().activeDOMObjects().size();
 }
 
 void ExecutionContext::suspendScheduledTasks()
 {
     suspendActiveDOMObjects();
     if (m_client)
         m_client->tasksWereSuspended();
@@ skipping 224 matching lines @@
 
     RELEASE_ASSERT(m_client);
     // The SandboxOrigin is stored redundantly in the security origin.
     if (isSandboxed(SandboxOrigin) && m_client->securityContext().securityOrigin() && !m_client->securityContext().securityOrigin()->isUnique()) {
         m_client->securityContext().setSecurityOrigin(SecurityOrigin::createUnique());
         m_client->didUpdateSecurityOrigin();
     }
 }
 
 } // namespace WebCore