Revert of Revert of Reland factor out window proxy management portions of ScriptController.

Source/bindings/core/v8/WindowProxy.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 227 matching lines @@
     if (m_frame->isLocalFrame()) {
         LocalFrame* frame = toLocalFrame(m_frame);
         InspectorInstrumentation::didCreateScriptContext(frame, m_scriptState.get(), origin, m_world->isMainWorld());
         frame->loader().client()->didCreateScriptContext(context, m_world->extensionGroup(), m_world->worldId());
     }
     return true;
 }
 
 void WindowProxy::createContext()
 {
-    // This can get called after a frame is already detached...
-    // FIXME: Fix the code so we don't need this check.
-    if (m_frame->isLocalFrame() && !toLocalFrame(m_frame)->loader().documentLoader())
+    if (!m_frame->client())
         return;
 
     // Create a new environment using an empty template for the shadow
     // object. Reuse the global object if one has been created earlier.
     v8::Local<v8::ObjectTemplate> globalTemplate = V8Window::getShadowObjectTemplate(m_isolate);
     if (globalTemplate.IsEmpty())
         return;
 
     double contextCreationStartInSeconds = currentTime();
 
@@ skipping 226 matching lines @@
 
 void WindowProxy::updateSecurityOrigin(SecurityOrigin* origin)
 {
     ASSERT(m_world->isMainWorld());
     if (!isContextInitialized())
         return;
     setSecurityToken(origin);
 }
 
 } // namespace blink