change the IsolatedContext to have a test version of the AccountManager that...

        mMainHandler = new Handler(mContext.getMainLooper());

    }

    /**

     * @hide used for testing only

     */

    public AccountManager(Context context, IAccountManager service, Handler handler) {

        mContext = context;

        mService = service;

        mMainHandler = handler;

    }

    public static AccountManager get(Context context) {

        return (AccountManager) context.getSystemService(Context.ACCOUNT_SERVICE);

    }

import com.google.android.collect.Lists;

import android.accounts.AccountManager;

import android.accounts.OnAccountsUpdatedListener;

import android.content.ContextWrapper;

import android.content.ContentResolver;

import android.content.Intent;

import android.content.IntentFilter;

import android.content.pm.PackageManager;

import android.net.Uri;

import android.os.Handler;

import android.os.Looper;

import java.util.List;

public class IsolatedContext extends ContextWrapper {

    private ContentResolver mResolver;

    private final MockAccountManager mMockAccountManager;

    private List<Intent> mBroadcastIntents = Lists.newArrayList();

            ContentResolver resolver, Context targetContext) {

        super(targetContext);

        mResolver = resolver;

        mMockAccountManager = new MockAccountManager();

    }

    /** Returns the list of intents that were broadcast since the last call to this method. */

    @Override

    public Object getSystemService(String name) {

        // No services exist in this context.

        if (Context.ACCOUNT_SERVICE.equals(name)) {

            return mMockAccountManager;

        }

        // No other services exist in this context.

        return null;

    }

    private class MockAccountManager extends AccountManager {

        public MockAccountManager() {

            super(IsolatedContext.this, null /* IAccountManager */, null /* handler */);

        }

        public void addOnAccountsUpdatedListener(OnAccountsUpdatedListener listener,

                Handler handler, boolean updateImmediately) {

            // do nothing

        }

    }

}