extensions: Cleanup class/struct fwd declarations

extensions/browser/api/networking_private/networking_private_event_router.h

 // Copyright 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 EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_EVENT_ROUTER_H_
 #define EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_EVENT_ROUTER_H_
 
 #include "base/macros.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "extensions/browser/event_router.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
-class NetworkingPrivateDelegate;
-
 // This is an event router that will observe listeners to |NetworksChanged| and
 // |NetworkListChanged| events. On ChromeOS it will forward these events
 // from the NetworkStateHandler to the JavaScript Networking API.
 class NetworkingPrivateEventRouter : public KeyedService,
                                      public EventRouter::Observer {
  public:
   static NetworkingPrivateEventRouter* Create(
       content::BrowserContext* browser_context);
 
  protected:
   NetworkingPrivateEventRouter() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NetworkingPrivateEventRouter);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_EVENT_ROUTER_H_