Add help button to app launcher

ui/app_list/app_list_menu.cc

 // 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.
 
 #include "ui/app_list/app_list_menu.h"
 
 #include "grit/ui_strings.h"
 #include "ui/app_list/app_list_view_delegate.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/menu_separator_types.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace app_list {
 
 AppListMenu::AppListMenu(AppListViewDelegate* delegate)
     : menu_model_(this),
       delegate_(delegate) {
   InitMenu();
 }
 
 AppListMenu::~AppListMenu() {}
 
 void AppListMenu::InitMenu() {
   menu_model_.AddItem(CURRENT_USER, string16());
   menu_model_.AddSeparator(ui::NORMAL_SEPARATOR);
 
   menu_model_.AddItem(SHOW_SETTINGS, l10n_util::GetStringUTF16(
       IDS_APP_LIST_OPEN_SETTINGS));
 
+  menu_model_.AddItem(SHOW_HELP, l10n_util::GetStringUTF16(
+      IDS_APP_LIST_HELP));
+
   menu_model_.AddItem(SHOW_FEEDBACK, l10n_util::GetStringUTF16(
       IDS_APP_LIST_OPEN_FEEDBACK));
 }
 
 bool AppListMenu::IsCommandIdChecked(int command_id) const {
   return false;
 }
 
 bool AppListMenu::IsCommandIdEnabled(int command_id) const {
   return true;
 }
 
 bool AppListMenu::GetAcceleratorForCommandId(int command_id,
                                              ui::Accelerator* accelerator) {
   return false;
 }
 
 void AppListMenu::ExecuteCommand(int command_id, int event_flags) {
   switch (command_id) {
     case CURRENT_USER:
       break;  // Do nothing.
     case SHOW_SETTINGS:
       delegate_->OpenSettings();
       break;
+    case SHOW_HELP:
+      delegate_->OpenHelp();
+      break;
     case SHOW_FEEDBACK:
       delegate_->OpenFeedback();
       break;
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace app_list