- make an AccountManager per context, not one per process

     * Add a {@link OnAccountsUpdatedListener} to this instance of the {@link AccountManager}.

     * The listener is guaranteed to be invoked on the thread of the Handler that is passed

     * in or the main thread's Handler if handler is null.

     * <p>

     * You must remove this listener before the context that was used to retrieve this

     * {@link AccountManager} instance goes away. This generally means when the Activity

     * or Service you are running is stopped.

     * @param listener the listener to add

     * @param handler the Handler whose thread will be used to invoke the listener. If null

     * the AccountManager context's main thread will be used.

    private final static boolean DEBUG_ICONS = false;

    private static final Object sSync = new Object();

    private static AccountManager sAccountManager;

    private static AlarmManager sAlarmManager;

    private static PowerManager sPowerManager;

    private static ConnectivityManager sConnectivityManager;

    private boolean mIsBluetoothAdapterCached = false;

    private BluetoothAdapter mBluetoothAdapter;

    private boolean mRestricted;

    private AccountManager mAccountManager; // protected by mSync

    private final Object mSync = new Object();

    }

    private AccountManager getAccountManager() {

        synchronized (sSync) {

            if (sAccountManager == null) {

        synchronized (mSync) {

            if (mAccountManager == null) {

                IBinder b = ServiceManager.getService(ACCOUNT_SERVICE);

                IAccountManager service = IAccountManager.Stub.asInterface(b);

                sAccountManager = new AccountManager(this, service);

                mAccountManager = new AccountManager(this, service);

            }

            return mAccountManager;

        }

        return sAccountManager;

    }

    private ActivityManager getActivityManager() {