Drop more dependencies of ProfileKeyedService infrastructure on chrome.

chrome/browser/extensions/token_cache/token_cache_service_factory.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_TOKEN_CACHE_TOKEN_CACHE_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_EXTENSIONS_TOKEN_CACHE_TOKEN_CACHE_SERVICE_FACTORY_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
 
+class Profile;
+
 namespace extensions {
 class TokenCacheService;
 }  // namespace extensions
 
 class TokenCacheServiceFactory : public ProfileKeyedServiceFactory {
  public:
   static extensions::TokenCacheService* GetForProfile(Profile* profile);
   static TokenCacheServiceFactory* GetInstance();
 
  private:
   TokenCacheServiceFactory();
   virtual ~TokenCacheServiceFactory();
 
   friend struct DefaultSingletonTraits<TokenCacheServiceFactory>;
 
   // Inherited from ProfileKeyedServiceFactory:
   virtual ProfileKeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const OVERRIDE;
 
    DISALLOW_COPY_AND_ASSIGN(TokenCacheServiceFactory);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_TOKEN_CACHE_TOKEN_CACHE_SERVICE_FACTORY_H_