components: Cleanup class/struct fwd declarations

components/omnibox/browser/zero_suggest_provider.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.
 //
 // This file contains the zero-suggest autocomplete provider. This experimental
 // provider is invoked when the user focuses in the omnibox prior to editing,
 // and generates search query suggestions based on the current URL.
 
 #ifndef COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_
 #define COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/metrics/proto/omnibox_event.pb.h"
 #include "components/omnibox/browser/base_search_provider.h"
 #include "components/omnibox/browser/search_provider.h"
 #include "net/url_request/url_fetcher_delegate.h"
 
 class AutocompleteProviderListener;
 class HistoryURLProvider;
 
 namespace base {
-class ListValue;
 class Value;
 }
 
 namespace net {
 class URLFetcher;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
@@ skipping 123 matching lines @@
   // Whether we are waiting for a most visited visited urls callback to run.
   bool waiting_for_most_visited_urls_request_;
 
   // For callbacks that may be run after destruction.
   base::WeakPtrFactory<ZeroSuggestProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ZeroSuggestProvider);
 };
 
 #endif  // COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_