Get rid of unnecessary forward declarations in components/autofill/

components/autofill/core/browser/webdata/autofill_webdata_backend_impl.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 COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/ref_counted_delete_on_message_loop.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/supports_user_data.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata_backend.h"
 #include "components/autofill/core/common/form_field_data.h"
 #include "components/webdata/common/web_data_results.h"
 #include "components/webdata/common/web_data_service_base.h"
 #include "components/webdata/common/web_data_service_consumer.h"
 #include "components/webdata/common/web_database.h"
 
 namespace base {
 class MessageLoopProxy;
 }
 
 class WebDataServiceBackend;
 
 namespace autofill {
 
-class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataServiceObserverOnDBThread;
 class CreditCard;
 
 // Backend implentation for the AutofillWebDataService. This class runs on the
 // DB thread, as it handles reads and writes to the WebDatabase, and functions
 // in it should only be called from that thread. Most functions here are just
 // the implementations of the corresponding functions in the Autofill
 // WebDataService.
 // This class is destroyed on the DB thread.
@@ skipping 150 matching lines @@
   scoped_refptr<WebDataServiceBackend> web_database_backend_;
 
   base::Closure on_changed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillWebDataBackendImpl);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_