message: Better position the drop indicator when at the end of the tab row
diff: @@ -522,7 +522,8 @@ export class TabWidget extends ThemeableElementBase {
  // Right of the tab bar.
  const kid = childElements[childElements.length-1];
  const kidRect = kid.getBoundingClientRect();
  - indicatorX = Math.floor((kidRect.right + wholeWidgetRect.right) /2);
  + const style = window.getComputedStyle(kid);
  + indicatorX = Math.floor(kidRect.right) + DomUtils.pixelLengthToInt(style.marginRight);
  }
  } else {
  indicatorX = Math.floor((wholeWidgetRect.left + wholeWidgetRect.right) /2);
  