chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/login/signin/merge_session_resource_throttle.h

 // Copyright 2015 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_LOGIN_SIGNIN_MERGE_SESSION_RESOURCE_THROTTLE_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_MERGE_SESSION_RESOURCE_THROTTLE_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "content/public/browser/resource_throttle.h"
 
-class GURL;
-
 namespace net {
 class URLRequest;
 }
 
 class MergeSessionResourceThrottle : public content::ResourceThrottle {
  public:
   explicit MergeSessionResourceThrottle(net::URLRequest* request);
   ~MergeSessionResourceThrottle() override;
 
  private:
   // content::ResourceThrottle implementation:
   void WillStartRequest(bool* defer) override;
   const char* GetNameForLogging() const override;
 
   // MergeSessionXHRRequestWaiter callback.
   void OnBlockingPageComplete();
 
   // Not owned.
   net::URLRequest* request_;
 
   base::WeakPtrFactory<MergeSessionResourceThrottle> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MergeSessionResourceThrottle);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_MERGE_SESSION_RESOURCE_THROTTLE_H_