maybeSendMediaInfoMessage_() {
    if (this.initialStatusUpdatePending_ &&
        (this.video_.duration || this.player_.isLive())) {
      // Send over a media status message to set the duration of the cast
      // dialogue.
      this.sendMediaInfoMessage_();
      this.initialStatusUpdatePending_ = false;
      return true;
    }
    return false;
  }
Composes and sends a mediaStatus message if appropriate.
@return {boolean}
@private