chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/api/omnibox/omnibox_api.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 CHROME_BROWSER_EXTENSIONS_API_OMNIBOX_OMNIBOX_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_OMNIBOX_OMNIBOX_API_H_
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "chrome/browser/extensions/extension_icon_manager.h"
 #include "chrome/common/extensions/api/omnibox.h"
 #include "components/omnibox/browser/autocomplete_match.h"
 #include "components/search_engines/template_url_service.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "ui/base/window_open_disposition.h"
 
 class Profile;
 class TemplateURL;
 class TemplateURLService;
 
-namespace base {
-class ListValue;
-}
-
 namespace content {
 class BrowserContext;
 class WebContents;
 }
 
 namespace gfx {
 class Image;
 }
 
 namespace extensions {
@@ skipping 129 matching lines @@
     AutocompleteMatch* match);
 
 // This function converts style information populated by the JSON schema
 // // compiler into an ACMatchClassifications object.
 ACMatchClassifications StyleTypesToACMatchClassifications(
     const api::omnibox::SuggestResult &suggestion);
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_OMNIBOX_OMNIBOX_API_H_