removed unused code

lib/browser-polyfill/custom-browser-polyfill.js

@@ -208,19 +208,7 @@
 						}
 					})
 				),
-				getPlatformInfo: () => new Promise((resolve, reject) =>
-					chrome.runtime.getPlatformInfo(info => {
-						if (chrome.runtime.lastError) {
-							reject(chrome.runtime.lastError);
-						} else {
-							resolve(info);
-						}
-					})
-				),
 				getURL: (path) => chrome.runtime.getURL(path),
-				onInstalled: {
-					addListener: listener => chrome.runtime.onInstalled.addListener(listener)
-				},
 				get lastError() {
 					return chrome.runtime.lastError;
 				}