Implement local storage for App List in case app sync is off.

chrome/browser/ui/ash/chrome_launcher_prefs.cc

 // Copyright (c) 2012 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/ui/ash/chrome_launcher_prefs.h"
 
 #include <stddef.h>
 
 #include <set>
 
@@ skipping 580 matching lines @@
   }
 
   return legacy_pins;
 }
 
 std::vector<AppLauncherId> GetPinnedAppsFromPrefs(
     const PrefService* prefs,
     LauncherControllerHelper* helper) {
   app_list::AppListSyncableService* app_service =
       app_list::AppListSyncableServiceFactory::GetForProfile(helper->profile());
-  // Some unit tests may not have it.
-  if (!app_service)
+  // Some unit tests may not have it or service may not be initialized.
+  if (!app_service || !app_service->IsInitialized())
     return std::vector<AppLauncherId>();
 
   std::vector<PinInfo> pin_infos;
 
   AppTracker policy_apps;
   GetAppsPinnedByPolicy(prefs, helper, &policy_apps);
 
   // Empty pins indicates that sync based pin model is used for the first
   // time. In normal workflow we have at least Chrome browser pin info.
   bool first_run = true;
@@ skipping 125 matching lines @@
     pin_position = position_before.CreateAfter();
   else if (position_after.IsValid())
     pin_position = position_after.CreateBefore();
   else
     pin_position = syncer::StringOrdinal::CreateInitialOrdinal();
   app_service->SetPinPosition(app_launcher_id_str, pin_position);
 }
 
 }  // namespace launcher
 }  // namespace ash