Clean up forward declarations in Source/platform

Source/platform/network/ResourceLoadTiming.h

 /*
  * 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 
 #ifndef ResourceLoadTiming_h
 #define ResourceLoadTiming_h
 
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
-class DocumentLoadTiming;
-
 class ResourceLoadTiming : public RefCounted<ResourceLoadTiming> {
 public:
     static PassRefPtr<ResourceLoadTiming> create()
     {
         return adoptRef(new ResourceLoadTiming);
     }
 
     PassRefPtr<ResourceLoadTiming> deepCopy()
     {
         RefPtr<ResourceLoadTiming> timing = create();
@@ skipping 67 matching lines @@
         , receiveHeadersEnd(0)
         , sslStart(0)
         , sslEnd(0)
     {
     }
 };
 
 }
 
 #endif