removed obsolete test

lib/browser-polyfill/chrome-browser-polyfill.js

@@ -18,15 +18,11 @@
  *   along with SingleFile.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* global navigator */
-
 (() => {
 
-	const isChrome = navigator.userAgent.includes("Chrome");
-
 	const FEATURE_TESTS = {};
 
-	if (isChrome && !this.browser && this.chrome) {
+	if (!this.browser && this.chrome) {
 		const nativeAPI = this.chrome;
 		this.__defineGetter__("browser", () => ({
 			browserAction: {