src/vs/editor/contrib/find/browser/findWidget.ts/FindWidget/_layoutViewZone
class FindWidget:	private _layoutViewZone(targetScrollTop?: number) {
		const addExtraSpaceOnTop = this._codeEditor.getOption(EditorOption.find).addExtraSpaceOnTop;

		if (!addExtraSpaceOnTop) {
			this._removeViewZone();
			return;
		}

		if (!this._isVisible) {
			return;
		}
		const viewZone = this._viewZone;
		if (this._viewZoneId !== undefined || !viewZone) {
			return;
		}

		this._codeEditor.changeViewZones((accessor) => {
			viewZone.heightInPx = this._getHeight();
			this._viewZoneId = accessor.addZone(viewZone);
			// scroll top adjust to make sure the editor doesn't scroll when adding viewzone at the beginning.
			this._codeEditor.setScrollTop(targetScrollTop || this._codeEditor.getScrollTop() + viewZone.heightInPx);
		});
	}