Oilpan: have FrameFetchContext keep a DocumentLoader member.

Source/core/loader/FrameFetchContext.cpp

 /*
  * Copyright (C) 2013 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 179 matching lines @@
     }
     return UseProtocolCachePolicy;
 }
 
 // FIXME(http://crbug.com/274173):
 // |loader| can be null if the resource is loaded from imported document.
 // This means inspector, which uses DocumentLoader as an grouping entity,
 // cannot see imported documents.
 inline DocumentLoader* FrameFetchContext::ensureLoaderForNotifications()
 {
-    return m_documentLoader ? m_documentLoader : frame()->loader().documentLoader();
+    return m_documentLoader ? m_documentLoader.get() : frame()->loader().documentLoader();
 }
 
 void FrameFetchContext::dispatchDidChangeResourcePriority(unsigned long identifier, ResourceLoadPriority loadPriority, int intraPriorityValue)
 {
     frame()->loader().client()->dispatchDidChangeResourcePriority(identifier, loadPriority, intraPriorityValue);
 }
 
 void FrameFetchContext::dispatchWillSendRequest(unsigned long identifier, ResourceRequest& request, const ResourceResponse& redirectResponse, const FetchInitiatorInfo& initiatorInfo)
 {
     frame()->loader().applyUserAgent(request);
@@ skipping 446 matching lines @@
 }
 
 bool FrameFetchContext::isLowPriorityIframe() const
 {
     return !frame()->isMainFrame() && frame()->settings() && frame()->settings()->lowPriorityIframes();
 }
 
 DEFINE_TRACE(FrameFetchContext)
 {
     visitor->trace(m_document);
+    visitor->trace(m_documentLoader);
     FetchContext::trace(visitor);
 }
 
 } // namespace blink