src/vs/base/parts/quickinput/browser/quickInputBox.ts/QuickInputBox/onMouseDown
class QuickInputBox:	onMouseDown = (handler: (event: StandardMouseEvent) => void): IDisposable => {
		return dom.addDisposableListener(this.findInput.inputBox.inputElement, dom.EventType.MOUSE_DOWN, (e: MouseEvent) => {
			handler(new StandardMouseEvent(e));
		});
	};