Merge "AudioFinger: Release buffers in AudioMixer when track becomes inactive" into pi-dev

        track->reset();

    }

    // Track destruction may occur outside of threadLoop once it is removed from active tracks.

    // Ensure the AudioMixer doesn't have a raw "buffer provider" pointer to the track if

    // it ceases to be active, to allow safe removal from the AudioMixer at the start

    // of prepareTracks_l(); this releases any outstanding buffer back to the track.

    // See also the implementation of destroyTrack_l().

    for (const auto &track : *tracksToRemove) {

        const int name = track->name();

        if (mAudioMixer->exists(name)) { // Normal tracks here, fast tracks in FastMixer.

            mAudioMixer->setBufferProvider(name, nullptr /* bufferProvider */);

        }

    }

    // remove all the tracks that need to be...

    removeTracks_l(*tracksToRemove);