MemoryCache: Enable MemoryCache to have multiple isolated resource maps

Source/core/loader/ImageLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 347 matching lines @@
         url = document.completeURL(sourceURI(imageSourceURL));
     return url;
 }
 
 bool ImageLoader::shouldLoadImmediately(const KURL& url, LoadType loadType) const
 {
     return (m_loadingImageDocument
         || isHTMLObjectElement(m_element)
         || isHTMLEmbedElement(m_element)
         || url.protocolIsData()
-        || memoryCache()->resourceForURL(url)
+        || memoryCache()->resourceForURL(url, m_element->document().fetcher()->getCacheIdentifier())
         || loadType == ForceLoadImmediately);
 }
 
 void ImageLoader::notifyFinished(Resource* resource)
 {
     WTF_LOG(Timers, "ImageLoader::notifyFinished %p; m_hasPendingLoadEvent=%d",
         this, m_hasPendingLoadEvent);
 
     ASSERT(m_failedLoadURL.isEmpty());
     ASSERT(resource == m_image.get());
@@ skipping 193 matching lines @@
 }
 
 #if ENABLE(OILPAN)
 ImageLoader::ImageLoaderClientRemover::~ImageLoaderClientRemover()
 {
     m_loader.willRemoveClient(m_client);
 }
 #endif
 
 }