src/vs/base/browser/browser.ts/DevicePixelRatioMonitor/_handleChange
class DevicePixelRatioMonitor:	private _handleChange(fireEvent: boolean): void {
		if (this._mediaQueryList) {
			this._mediaQueryList.removeEventListener('change', this._listener);
		}

		this._mediaQueryList = matchMedia(`(resolution: ${window.devicePixelRatio}dppx)`);
		this._mediaQueryList.addEventListener('change', this._listener);

		if (fireEvent) {
			this._onDidChange.fire();
		}
	}