handleImageEvent_(e) {
    if (this.getAborted()) {
      this.markCompleted_();
      return;
    }
    switch (e.type) {
      case goog.events.EventType.LOAD:
        this.handleSuccess_(e);
        this.markCompleted_();
        break;

      case goog.net.EventType.ERROR:
      case goog.net.EventType.ABORT:
        this.handleError_(e);
        break;
    }
  }
Handles all events fired by the ImageLoader object for a given request.
@param {goog.events.Event} e The event.
@private