src/vs/workbench/services/history/browser/historyService.ts/HistoryService/onMouseDown
class HistoryService:	private onMouseDown(event: MouseEvent): void {

		// Support to navigate in history when mouse buttons 4/5 are pressed
		switch (event.button) {
			case 3:
				EventHelper.stop(event);
				this.goBack();
				break;
			case 4:
				EventHelper.stop(event);
				this.goForward();
				break;
		}
	}