chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/api/launcher_page/launcher_page_api.h

 // Copyright 2014 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_LAUNCHER_PAGE_LAUNCHER_PAGE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_LAUNCHER_PAGE_LAUNCHER_PAGE_API_H_
 
 #include "base/macros.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 
 namespace app_list {
 class AppListSyncableService;
-class AppListModel;
 }
 
 namespace extensions {
 
 class LauncherPageAPI : public BrowserContextKeyedAPI {
  public:
   explicit LauncherPageAPI(content::BrowserContext* context);
   ~LauncherPageAPI() override;
 
   app_list::AppListSyncableService* GetService() const;
@@ skipping 68 matching lines @@
 
   ResponseAction Run() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LauncherPageSetEnabledFunction);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_LAUNCHER_PAGE_LAUNCHER_PAGE_API_H_