arc: Fix ArcPackageSyncableService initialization issue.

chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc

Index: chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc
diff --git a/chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc b/chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0fb112ff4b665cb6f54593f23d26223afe7ec103
--- /dev/null
+++ b/chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc
@@ -0,0 +1,33 @@
+// Copyright 2016 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/app_list/arc/arc_package_sync_data_type_controller.h"
+
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/app_list/arc/arc_app_list_prefs.h"
+#include "components/arc/common/app.mojom.h"
+#include "components/arc/instance_holder.h"
+#include "content/public/browser/browser_thread.h"
+
+ArcPackageSyncDataTypeController::ArcPackageSyncDataTypeController(
+    syncer::ModelType type,
+    const base::Closure& error_callback,
+    sync_driver::SyncClient* sync_client,
+    Profile* profile)
+    : sync_driver::UIDataTypeController(
+          content::BrowserThread::GetMessageLoopProxyForThread(
+              content::BrowserThread::UI),
+          error_callback,
+          type,
+          sync_client),
+      profile_(profile) {}
+
+ArcPackageSyncDataTypeController::~ArcPackageSyncDataTypeController() {}
+
+bool ArcPackageSyncDataTypeController::ReadyForStart() const {
+  ArcAppListPrefs* prefs = ArcAppListPrefs::Get(profile_);
+  if (prefs && prefs->app_instance_holder()->instance())
+    return true;
+  return false;
+}