extensions: Cleanup class/struct fwd declarations

extensions/browser/api/declarative/rules_registry_service.h

 // Copyright (c) 2012 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_DECLARATIVE_RULES_REGISTRY_SERVICE_H__
 #define EXTENSIONS_BROWSER_API_DECLARATIVE_RULES_REGISTRY_SERVICE_H__
 
 #include <map>
 #include <string>
 #include <tuple>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/scoped_observer.h"
 #include "extensions/browser/api/declarative/rules_registry.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_registry_observer.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 class ContentRulesRegistry;
 class ExtensionRegistry;
-class RulesRegistryStorageDelegate;
 }
 
 namespace extensions {
 
 // This class owns all RulesRegistries implementations of an ExtensionService.
 // This class lives on the UI thread.
 class RulesRegistryService : public BrowserContextKeyedAPI,
                              public ExtensionRegistryObserver {
  public:
   static const int kDefaultRulesRegistryID;
@@ skipping 105 matching lines @@
       extension_registry_observer_;
 
   content::BrowserContext* browser_context_;
 
   DISALLOW_COPY_AND_ASSIGN(RulesRegistryService);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_DECLARATIVE_RULES_REGISTRY_SERVICE_H__