Do not sync ARC opt-in preference

chrome/browser/chromeos/arc/arc_auth_service.cc

 // Copyright 2015 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 "chrome/browser/chromeos/arc/arc_auth_service.h"
 
 #include <utility>
 
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/wm_shell.h"
@@ skipping 135 matching lines @@
 
 // static
 ArcAuthService* ArcAuthService::Get() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   return g_arc_auth_service;
 }
 
 // static
 void ArcAuthService::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
-  registry->RegisterBooleanPref(
-      prefs::kArcEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  // TODO(dspaid): Implement a mechanism to allow this to sync on first boot
+  // only.
+  registry->RegisterBooleanPref(prefs::kArcEnabled, false);
   registry->RegisterBooleanPref(prefs::kArcSignedIn, false);
   registry->RegisterBooleanPref(prefs::kArcBackupRestoreEnabled, true);
   registry->RegisterBooleanPref(prefs::kArcLocationServiceEnabled, true);
 }
 
 // static
 void ArcAuthService::DisableUIForTesting() {
   g_disable_ui_for_testing = true;
 }
 
@@ skipping 343 matching lines @@
     UpdateEnabledStateUMA(false);
     profile_->GetPrefs()->SetBoolean(prefs::kArcSignedIn, false);
   }
   ShutdownBridgeAndCloseUI();
 }
 
 void ArcAuthService::OnOptInPreferenceChanged() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK(profile_);
 
+  // TODO(dspaid): Move code from OnSyncedPrefChanged into this method.
+  OnSyncedPrefChanged(prefs::kArcEnabled, IsArcManaged());
+
   const bool arc_enabled = IsArcEnabled();
   FOR_EACH_OBSERVER(Observer, observer_list_, OnOptInEnabled(arc_enabled));
 
   if (!arc_enabled) {
     StopArc();
     return;
   }
 
   if (state_ == State::ACTIVE)
     return;
@@ skipping 274 matching lines @@
       return os << kStateFetchingCode;
     case ArcAuthService::State::ACTIVE:
       return os << kStateActive;
     default:
       NOTREACHED();
       return os;
   }
 }
 
 }  // namespace arc