Coerce offset to number in renderer process

lib/renderer/window-setup.js

@@ -164,7 +164,7 @@ module.exports = (ipcRenderer, guestInstanceId, openerId, hiddenPage) => {
   }
 
   window.history.go = function (offset) {
-    sendHistoryOperation(ipcRenderer, 'goToOffset', offset)
+    sendHistoryOperation(ipcRenderer, 'goToOffset', +offset)
   }
 
   defineProperty(window.history, 'length', {