Show an InfoBar when trying to start Packaged Apps from Metro mode.

apps/prefs.cc

Index: apps/prefs.cc
diff --git a/apps/prefs.cc b/apps/prefs.cc
index b883fbb456c23e89191057cfba300fc9a1834a88..6a0137ba05ed68eb577ca29bf8600a3f02da829b 100644
--- a/apps/prefs.cc
+++ b/apps/prefs.cc
@@ -20,6 +20,11 @@ void RegisterPrefs(PrefRegistrySimple* registry) {
   // GetIsAppLauncherEnabled().
   registry->RegisterBooleanPref(prefs::kAppLauncherIsEnabled,
                                 MaybeIsAppLauncherEnabled());
+
+#if defined(OS_WIN)
+  registry->RegisterStringPref(prefs::kRestartFromMetroWithAppLaunch, "");
+  registry->RegisterStringPref(prefs::kRestartFromMetroWithProfileDir, "");
+#endif
 }
 
 }  // namespace apps