Clarify when what notifications are send when a window object is cleared

Source/bindings/v8/ScriptController.cpp

 /*
  * Copyright (C) 2008, 2009 Google Inc. All rights reserved.
  * Copyright (C) 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 220 matching lines @@
     else {
         IsolatedWorldMap::iterator iter = m_isolatedWorlds.find(world.worldId());
         if (iter != m_isolatedWorlds.end())
             shell = iter->value.get();
         else {
             OwnPtr<V8WindowShell> isolatedWorldShell = V8WindowShell::create(m_frame, world, m_isolate);
             shell = isolatedWorldShell.get();
             m_isolatedWorlds.set(world.worldId(), isolatedWorldShell.release());
         }
     }
-    if (!shell->isContextInitialized() && shell->initializeIfNeeded())
-        m_frame->loader().dispatchDidClearWindowObjectInWorld(world);
+    if (!shell->isContextInitialized() && shell->initializeIfNeeded() && world.isMainWorld())
+        m_frame->loader().dispatchDidClearWindowObjectInMainWorld();
     return shell;
 }
 
 bool ScriptController::shouldBypassMainWorldContentSecurityPolicy()
 {
     v8::Handle<v8::Context> context = m_isolate->GetCurrentContext();
     if (context.IsEmpty() || !toDOMWindow(context))
         return false;
     DOMWrapperWorld& world = DOMWrapperWorld::current(m_isolate);
     return world.isIsolatedWorld() ? world.isolatedWorldHasContentSecurityPolicy() : false;
@@ skipping 374 matching lines @@
         resultArray->Set(i, evaluationResult);
     }
 
     if (results) {
         for (size_t i = 0; i < resultArray->Length(); ++i)
             results->append(ScriptValue(ScriptState::from(context), resultArray->Get(i)));
     }
 }
 
 } // namespace WebCore