Merge "MidiManager: use ConcurrentHashMap" into mnc-dev

import android.os.RemoteException;

import android.util.Log;

import java.util.HashMap;

import java.util.concurrent.ConcurrentHashMap;

/**

 * This class is the public application interface to the MIDI service.

    private final IMidiManager mService;

    private final IBinder mToken = new Binder();

    private HashMap<DeviceCallback,DeviceListener> mDeviceListeners =

        new HashMap<DeviceCallback,DeviceListener>();

    private ConcurrentHashMap<DeviceCallback,DeviceListener> mDeviceListeners =

        new ConcurrentHashMap<DeviceCallback,DeviceListener>();

    // Binder stub for receiving device notifications from MidiService

    private class DeviceListener extends IMidiDeviceListener.Stub {