Fix Mutex::timedLock to properly handle relative time

    status_t    tryLock();

#if defined(__ANDROID__)

    // lock the mutex, but don't wait longer than timeoutMilliseconds.

    // Lock the mutex, but don't wait longer than timeoutNs (relative time).

    // Returns 0 on success, TIMED_OUT for failure due to timeout expiration.

    //

    // OSX doesn't have pthread_mutex_timedlock() or equivalent. To keep

    // capabilities consistent across host OSes, this method is only available

    // when building Android binaries.

    status_t    timedLock(nsecs_t timeoutMilliseconds);

    //

    // FIXME?: pthread_mutex_timedlock is based on CLOCK_REALTIME,

    // which is subject to NTP adjustments, and includes time during suspend,

    // so a timeout may occur even though no processes could run.

    // Not holding a partial wakelock may lead to a system suspend.

    status_t    timedLock(nsecs_t timeoutNs);

#endif

    // Manages the mutex automatically. It'll be locked when Autolock is

}

#if defined(__ANDROID__)

inline status_t Mutex::timedLock(nsecs_t timeoutNs) {

    timeoutNs += systemTime(SYSTEM_TIME_REALTIME);

    const struct timespec ts = {

        /* .tv_sec = */ static_cast<time_t>(timeoutNs / 1000000000),

        /* .tv_nsec = */ static_cast<long>(timeoutNs % 1000000000),