Make DocumentLoader::timing return a reference

Source/core/timing/PerformanceNavigation.cpp

 /*
  * Copyright (C) 2010 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 52 matching lines @@
 
 unsigned short PerformanceNavigation::redirectCount() const
 {
     if (!m_frame)
         return 0;
 
     DocumentLoader* loader = m_frame->loader().documentLoader();
     if (!loader)
         return 0;
 
-    DocumentLoadTiming* timing = loader->timing();
-    if (timing->hasCrossOriginRedirect())
+    const DocumentLoadTiming& timing = loader->timing();
+    if (timing.hasCrossOriginRedirect())
         return 0;
 
-    return timing->redirectCount();
+    return timing.redirectCount();
 }
 
 void PerformanceNavigation::trace(Visitor* visitor)
 {
     DOMWindowProperty::trace(visitor);
 }
 
 } // namespace blink