Add policy for fullscreen mode; disallow fullscreen in public sessions

apps/prefs.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 "apps/prefs.h"
 
 #include "apps/app_launcher.h"
 #include "apps/pref_names.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "components/user_prefs/pref_registry_syncable.h"
@@ skipping 20 matching lines @@
   registry->RegisterStringPref(prefs::kAppLaunchForMetroRestartProfile, "");
 #endif
 
   // Identifies whether we should show the app launcher promo or not.
   // Now that a field trial also controls the showing, so the promo won't show
   // unless the pref is set AND the field trial is set to a proper group.
   registry->RegisterBooleanPref(prefs::kShowAppLauncherPromo, true);
 }
 
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
+#if !defined(OS_MACOSX)
+  registry->RegisterBooleanPref(
+      prefs::kAppFullscreenAllowed, true,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+#endif
+
   // Indicates whether app shortcuts have been created.
   registry->RegisterBooleanPref(
       prefs::kShortcutsHaveBeenCreated, false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 }  // namespace apps