Android: how to delete account from database which are displayed under "accounts and sync" from my own application

How can I delete google accounts from "accounts and sync"? I'm trying to call this line my app:

AccountManagerService.getSingleton().onServiceChanged(null,true);

whereas onServiceChanged() method is defined in AccountManagerService.java.

public void onServiceChanged(AuthenticatorDescription desc, boolean removed) {
    boolean accountDeleted = false;
    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    Cursor cursor = db.query(TABLE_ACCOUNTS,
            new String[]{ACCOUNTS_ID, ACCOUNTS_TYPE, ACCOUNTS_NAME},
            ACCOUNTS_TYPE + "=?", new String[]{desc.type}, null, null, null);
    try {
        while (cursor.moveToNext()) {
            final long accountId = cursor.getLong(0);
            final String accountType = cursor.getString(1);
            final String accountName = cursor.getString(2);
            Log.d(TAG, "deleting account " + accountName + " because type "
                    + accountType + " no longer has a registered authe开发者_StackOverflow中文版nticator");
            db.delete(TABLE_ACCOUNTS, ACCOUNTS_ID + "=" + accountId, null);
            accountDeleted = true;
        }
    } finally {
        cursor.close();
        if (accountDeleted) {
            sendAccountsChangedBroadcast();
        }
    }

This piece of code is not doing anything. I feel exception is being thrown which is handled at lower layer.

Try AccountManager.removeAccount.