Clean up forward declarations in Source/core

Source/core/fetch/FontResource.h

 /*
  * Copyright (C) 2007, 2008 Apple 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 17 matching lines @@
 
 #include "core/fetch/ResourceClient.h"
 #include "core/fetch/ResourcePtr.h"
 #include "platform/Timer.h"
 #include "platform/fonts/FontOrientation.h"
 #include "platform/fonts/FontWidthVariant.h"
 #include "wtf/OwnPtr.h"
 
 namespace blink {
 
-class Document;
 class ResourceFetcher;
 class FontPlatformData;
 class FontCustomPlatformData;
 
 class FontResource final : public Resource {
 public:
     typedef ResourceClient ClientType;
 
     FontResource(const ResourceRequest&);
     virtual ~FontResource();
@@ skipping 43 matching lines @@
     static ResourceClientType expectedType() { return FontType; }
     virtual ResourceClientType resourceClientType() const override final { return expectedType(); }
     virtual void fontLoaded(FontResource*) { }
     virtual void didStartFontLoad(FontResource*) { }
     virtual void fontLoadWaitLimitExceeded(FontResource*) { }
 };
 
 }
 
 #endif