Merge "Fix failure at AudioTrack_ListenerTest#testAudioTrackCallback" into oc-mr1-dev

    // Convert frame units to time units

    nsecs_t ns = NS_WHENEVER;

    if (minFrames != (uint32_t) ~0) {

        ns = framesToNanoseconds(minFrames, sampleRate, speed) + kWaitPeriodNs;

        // AudioFlinger consumption of client data may be irregular when coming out of device

        // standby since the kernel buffers require filling. This is throttled to no more than 2x

        // the expected rate in the MixerThread. Hence, we reduce the estimated time to wait by one

        // half (but no more than half a second) to improve callback accuracy during these temporary

        // data surges.

        const nsecs_t estimatedNs = framesToNanoseconds(minFrames, sampleRate, speed);

        constexpr nsecs_t maxThrottleCompensationNs = 500000000LL;

        ns = estimatedNs - min(estimatedNs / 2, maxThrottleCompensationNs) + kWaitPeriodNs;

        ns -= (timeAfterCallbacks - timeBeforeCallbacks);  // account for callback time

        // TODO: Should we warn if the callback time is too long?

        if (ns < 0) ns = 0;