chrome: Cleanup class/struct forward declarations

chrome/browser/ui/cocoa/profiles/user_manager_mac.h

 // Copyright 2014 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_UI_COCOA_PROFILES_USER_MANAGER_MAC_H_
 #define CHROME_BROWSER_UI_COCOA_PROFILES_USER_MANAGER_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include <memory>
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_window.h"
 #include "components/signin/core/browser/signin_metrics.h"
 
 @class ReauthDialogWindowController;
 @class UserManagerWindowController;
 
-namespace content {
-class NavigationController;
-class WebContents;
-}
-
 // Dialog widget that contains the Desktop User Manager webui. This object
 // should always be created from the UserManager::Show() method. Note that only
 // one User Manager will exist at a time.
 class UserManagerMac {
  public:
   // Called by the cocoa window controller when its window closes and the
   // controller destroyed itself. Deletes the instance.
   void WindowWasClosed();
 
   // Called from the UserManager class once the |system_profile| is ready. Will
@@ skipping 33 matching lines @@
   base::scoped_nsobject<ReauthDialogWindowController> reauth_window_;
 
   base::Time user_manager_started_showing_;
 
   base::FilePath signin_profile_path_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerMac);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_PROFILES_USER_MANAGER_MAC_H_