components: Cleanup class/struct fwd declarations

components/arc/intent_helper/arc_intent_helper_bridge.h

 // Copyright 2016 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 COMPONENTS_ARC_INTENT_HELPER_ARC_INTENT_HELPER_BRIDGE_H_
 #define COMPONENTS_ARC_INTENT_HELPER_ARC_INTENT_HELPER_BRIDGE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 11 matching lines @@
 
 class LinkHandlerModel;
 
 }  // namespace ash
 
 namespace arc {
 
 class ActivityIconLoader;
 class ArcBridgeService;
 class LocalActivityResolver;
-class SetWallpaperDelegate;
 
 // Receives intents from ARC.
 class ArcIntentHelperBridge
     : public ArcService,
       public InstanceHolder<mojom::IntentHelperInstance>::Observer,
       public mojom::IntentHelperHost,
       public ash::LinkHandlerModelFactory {
  public:
   enum class GetResult {
     // Failed. The intent_helper instance is not yet ready. This is a temporary
@@ skipping 54 matching lines @@
   scoped_refptr<LocalActivityResolver> activity_resolver_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcIntentHelperBridge);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_INTENT_HELPER_ARC_INTENT_HELPER_BRIDGE_H_