Add help button to app launcher

ui/app_list/app_list_menu.cc

Index: ui/app_list/app_list_menu.cc
diff --git a/ui/app_list/app_list_menu.cc b/ui/app_list/app_list_menu.cc
index c8e93b89a92b89c25bd750a5a5274d3d35111908..c3d464e22b1556af12065f5f353f1bcca7503307 100644
--- a/ui/app_list/app_list_menu.cc
+++ b/ui/app_list/app_list_menu.cc
@@ -27,6 +27,9 @@ void AppListMenu::InitMenu() {
   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));
 }
@@ -51,6 +54,9 @@ void AppListMenu::ExecuteCommand(int command_id, int event_flags) {
     case SHOW_SETTINGS:
       delegate_->OpenSettings();
       break;
+    case SHOW_HELP:
+      delegate_->OpenHelp();
+      break;
     case SHOW_FEEDBACK:
       delegate_->OpenFeedback();
       break;