Fix session.setPermissionRequestHandler webContents argument type

docs/api/session.md

@@ -287,7 +287,7 @@ win.webContents.session.setCertificateVerifyProc((request, callback) => {
 #### `ses.setPermissionRequestHandler(handler)`
 
 * `handler` Function
-  * `webContents` Object - [WebContents](web-contents.md) requesting the permission.
+  * `webContents` [WebContents](web-contents.md) - WebContents requesting the permission.
   * `permission` String - Enum of 'media', 'geolocation', 'notifications', 'midiSysex',
     'pointerLock', 'fullscreen', 'openExternal'.
   * `callback` Function