arc: Add Arc Kiosk app service and ability to launch kiosk apps.

chrome/browser/ui/app_list/arc/arc_app_list_prefs.h

Index: chrome/browser/ui/app_list/arc/arc_app_list_prefs.h
diff --git a/chrome/browser/ui/app_list/arc/arc_app_list_prefs.h b/chrome/browser/ui/app_list/arc/arc_app_list_prefs.h
index db0c9676a73b11d9e6fde3186a8748d724f536a8..f5520aa40dce1d4713aaa9ae8f01647ee9fbe0a7 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_list_prefs.h
+++ b/chrome/browser/ui/app_list/arc/arc_app_list_prefs.h
@@ -34,6 +34,10 @@ namespace arc {
 class ArcPackageSyncableService;
 }  // namespace arc
 
+namespace chromeos {
+class ArcKioskAppService;
+}  // namespace chromeos
+
 namespace content {
 class BrowserContext;
 }  // namespace content
@@ -374,7 +378,9 @@ class ArcAppListPrefs
   // True is Arc package list has been refreshed once.
   bool package_list_initial_refreshed_ = false;
 
-  arc::ArcPackageSyncableService* sync_service_;
+  arc::ArcPackageSyncableService* sync_service_ = nullptr;
+  // Track ARC kiosk app and auto-launches it if needed.
+  chromeos::ArcKioskAppService* kiosk_app_service_ = nullptr;
 
   mojo::Binding<arc::mojom::AppHost> binding_;