chrome: Cleanup class/struct forward declarations

chrome/browser/ui/webui/settings/settings_manage_profile_handler.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_UI_WEBUI_SETTINGS_SETTINGS_MANAGE_PROFILE_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_SETTINGS_MANAGE_PROFILE_HANDLER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/profiles/profile_attributes_storage.h"
 #include "chrome/browser/ui/webui/settings/settings_page_ui_handler.h"
 
-namespace base {
-class StringValue;
-}
-
 class Profile;
 
 namespace settings {
 
 // Chrome personal stuff profiles manage overlay UI handler.
 class ManageProfileHandler : public settings::SettingsPageUIHandler,
                              public ProfileAttributesStorage::Observer {
  public:
   explicit ManageProfileHandler(Profile* profile);
   ~ManageProfileHandler() override;
@@ skipping 57 matching lines @@
 
   // For generating weak pointers to itself for callbacks.
   base::WeakPtrFactory<ManageProfileHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ManageProfileHandler);
 };
 
 }  // namespace settings
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_SETTINGS_MANAGE_PROFILE_HANDLER_H_