Always consider playlists corresponding to different bandwidths different.

        bool firstTime = (mPlaylist == NULL);

        if ((ssize_t)bandwidthIndex != mPrevBandwidthIndex) {

            // If we switch bandwidths, do not pay any heed to whether

            // playlists changed since the last time...

            mPlaylist.clear();

        }

        bool unchanged;

        sp<M3UParser> playlist = fetchPlaylist(url.c_str(), &unchanged);

        if (playlist == NULL) {