Timer for Android

AndroidTimer.java

package com.skily.gps;

import android.os.Handler;
import java.util.concurrent.TimeUnit;
import timber.log.Timber;

public class AndroidTimer {
    long mTrackedTime = 0;
    long mLastUpdateTime = 0;

    Handler mTimerHandler = new Handler();
    Runnable mTimerRunnable = new Runnable() {
        @Override
        public void run() {
            long updateTime = System.currentTimeMillis();
            long millis = updateTime - mLastUpdateTime;
            mTrackedTime += TimeUnit.MILLISECONDS.toSeconds(millis);

            Timber.d("Tracked time: " + mTrackedTime);

            mTimerHandler.postDelayed(this, 1000);
            mLastUpdateTime = updateTime;
        }
    };

    public void startTimer() {
        mLastUpdateTime = System.currentTimeMillis();
        mTimerHandler.postDelayed(mTimerRunnable, 0);

        Timber.d("Timer started.");
    }

    public long stopTimer() {
        long trackedTime = mTrackedTime;

        mTrackedTime = 0;
        mTimerHandler.removeCallbacks(mTimerRunnable);

        Timber.d("Timer stopped.");

        return trackedTime;
    }

    public void pauseTimer() {
        mTimerHandler.removeCallbacks(mTimerRunnable);

        Timber.d("Timer paused.");
    }

    public void resumeTimer() {
        mLastUpdateTime = System.currentTimeMillis();
        mTimerHandler.postDelayed(mTimerRunnable, 0);

        Timber.d("Timer resumed.");
    }

    public long getTrackedTime() {
        return mTrackedTime;
    }
}