message: refactor(devtools): use safe operation to update the overlay
diff: import { Type } from '@angular/core';
  let overlay: any;
  -let overlayContent: any;
  +let overlayContent: HTMLElement;
  declare const ng: any;
  @@ -120,7 +120,11 @@ function showOverlay(
  overlay.style.top = ~~top + 'px';
  overlay.style.left = ~~left + 'px';
  - overlayContent.innerHTML = '';
  + while (overlayContent.children.length) {
  + const { children } = overlayContent;
  + overlayContent.removeChild(children[children.length - 1]);
  + }
  +
  content.forEach((child) => overlayContent.appendChild(child));
  document.body.appendChild(overlay);
  