[Devtools] Added ability to add extension columns to network

third_party/WebKit/Source/devtools/front_end/network_group_lookup/NetworkProductGroupLookup.js

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 /**
+ * @implements {Network.NetworkColumnExtensionInterface}
  * @implements {Network.NetworkGroupLookupInterface}
  */
 NetworkGroupLookup.NetworkProductGroupLookup = class {
   /**
    * @override
    * @param {!SDK.NetworkRequest} request
    * @return {?string}
    */
   lookup(request) {
     return ProductRegistry.nameForUrl(request.parsedURL);
   }
+  /**
+   * @override
+   * @param {!SDK.NetworkRequest} request
+   * @return {string}
+   */
+  lookupColumnValue(request) {
+    return this.lookup(request) || '';
+  }
 };