Make DocumentLoader::timing return a reference

Source/core/loader/DocumentLoader.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 95 matching lines @@
         NavigationType navigationType() const { return m_navigationType; }
         void setNavigationType(NavigationType navigationType) { m_navigationType = navigationType; }
 
         void setDefersLoading(bool);
 
         void startLoadingMainResource();
         void cancelMainResourceLoad(const ResourceError&);
 
         void attachThreadedDataReceiver(PassRefPtrWillBeRawPtr<ThreadedDataReceiver>);
         void acceptDataFromThreadedReceiver(const char* data, int dataLength, int encodedDataLength);
-        DocumentLoadTiming* timing() { return &m_documentLoadTiming; }
+        DocumentLoadTiming& timing() { return m_documentLoadTiming; }
+        const DocumentLoadTiming& timing() const { return m_documentLoadTiming; }
 
         ApplicationCacheHost* applicationCacheHost() const { return m_applicationCacheHost.get(); }
 
         bool isRedirect() const { return m_redirectChain.size() > 1; }
         void clearRedirectChain();
         void appendRedirect(const KURL&);
 
         PassRefPtr<ContentSecurityPolicy> releaseContentSecurityPolicy() { return m_contentSecurityPolicy.release(); }
 
     protected:
@@ skipping 73 matching lines @@
         double m_timeOfLastDataReceived;
 
         friend class ApplicationCacheHost;  // for substitute resource delivery
         OwnPtrWillBePersistent<ApplicationCacheHost> m_applicationCacheHost;
 
         RefPtr<ContentSecurityPolicy> m_contentSecurityPolicy;
     };
 }
 
 #endif // DocumentLoader_h