static isSupported(mimeType) {
    // Without MediaSource, our own parsers are useless.
    const device = shaka.device.DeviceFactory.getDevice();
    if (!device.supportsMediaSource()) {
      return false;
    }

    return shaka.media.ManifestParser.parsersByMime.has(mimeType);
  }
Determines whether or not the MIME type is supported by our own
manifest parsers on this platform.  This takes into account whether or not
MediaSource is available, as well as which parsers are registered to the
system.

@param {string} mimeType
@return {boolean}