chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/policy/policy_oauth2_token_fetcher.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_CHROMEOS_POLICY_POLICY_OAUTH2_TOKEN_FETCHER_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_POLICY_OAUTH2_TOKEN_FETCHER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "google_apis/gaia/gaia_auth_consumer.h"
 
-class GaiaAuthFetcher;
-class OAuth2AccessTokenFetcher;
-
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace policy {
 
 // Fetches the OAuth2 token for the device management service. Since Profile
 // creation might be blocking on a user policy fetch, this fetcher must always
 // send a (possibly empty) token to the callback, which will then let the policy
 // subsystem proceed and resume Profile creation. Sending the token even when no
@@ skipping 34 matching lines @@
   virtual const std::string& OAuth2RefreshToken() const = 0;
   virtual const std::string& OAuth2AccessToken() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PolicyOAuth2TokenFetcher);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_POLICY_OAUTH2_TOKEN_FETCHER_H_