chrome: Cleanup class/struct forward declarations

chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.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_UI_VIEWS_APPS_APP_INFO_DIALOG_APP_INFO_PERMISSIONS_PANEL_H_
 #define CHROME_BROWSER_UI_VIEWS_APPS_APP_INFO_DIALOG_APP_INFO_PERMISSIONS_PANEL_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "chrome/browser/ui/views/apps/app_info_dialog/app_info_panel.h"
 #include "extensions/common/permissions/permission_message_provider.h"
 
 class Profile;
 
 namespace extensions {
 class Extension;
 }
 
-namespace ui {
-class Event;
-}
-
-namespace views {
-class GridLayout;
-class View;
-}
-
 // The summary panel of the app info dialog, which provides basic information
 // and controls related to the app.
 class AppInfoPermissionsPanel : public AppInfoPanel {
  public:
   AppInfoPermissionsPanel(Profile* profile, const extensions::Extension* app);
 
   ~AppInfoPermissionsPanel() override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(AppInfoPermissionsPanelTest,
@@ skipping 21 matching lines @@
 
   int GetRetainedDeviceCount() const;
   base::string16 GetRetainedDeviceHeading() const;
   const std::vector<base::string16> GetRetainedDevices() const;
   void RevokeDevicePermissions();
 
   DISALLOW_COPY_AND_ASSIGN(AppInfoPermissionsPanel);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_APPS_APP_INFO_DIALOG_APP_INFO_PERMISSIONS_PANEL_H_