STR:
  - Go to https://mozilla.github.io/pdf.js/web/viewer.html
  - Click on "Open File" and open a pdf

The `Download` button and the `Current view` one just disappear.
I can reproduce this bug with Firefox nightly, Chrome stable and Epiphany on debian.
const { pdfViewer, supportedMouseWheelZoomModifierKeys } =
    PDFViewerApplication;
  if (pdfViewer.isInPresentationMode) {
    return;
  }
  if (
    (evt.ctrlKey && supportedMouseWheelZoomModifierKeys.ctrlKey) ||
    (evt.metaKey && supportedMouseWheelZoomModifierKeys.metaKey)
  ) {
    
    evt.preventDefault();
    
    if (zoomDisabledTimeout || document.visibilityState === "hidden") {
      return;
    }
    const previousScale = pdfViewer.currentScale;
    const delta = normalizeWheelEventDirection(evt);
    let ticks = 0;
    if (
      evt.deltaMode === WheelEvent.DOM_DELTA_LINE ||
      evt.deltaMode === WheelEvent.DOM_DELTA_PAGE
    ) {
      
      
      
      
      if (Math.abs(delta) >= 1) {
        ticks = Math.sign(delta);