DevTools: [hosted mode] avoid exception in devtools_compatibility:addExtensions

third_party/WebKit/Source/devtools/front_end/devtools_compatibility.js

 // Copyright 2014 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.
 /* eslint-disable indent */
 (function(window) {
 
   // DevToolsAPI ----------------------------------------------------------------
 
   /**
    * @unrestricted
@@ skipping 46 matching lines @@
       inspectorFrontendAPI[method].apply(inspectorFrontendAPI, args);
     }
 
     // API methods below this line --------------------------------------------
 
     /**
      * @param {!Array.<!ExtensionDescriptor>} extensions
      */
     addExtensions(extensions) {
       // Support for legacy front-ends (<M41).
-      if (window['WebInspector'] && window['WebInspector']['addExtensions'])
+      if (window['WebInspector'] && window['WebInspector']['addExtensions']) {
         window['WebInspector']['addExtensions'](extensions);
-      else
+      } else if (window['InspectorFrontendAPI']) {
+        // The addExtensions command is sent as the onload event happens for
+        // DevTools front-end. In case of DEBUG_DEVTOOLS/hosted mode, this

[dgozman, 2017/03/09 23:35:17]

That's only in hosted mode.

[lushnikov, 2017/03/10 02:27:58]

Done.

+        // happens before the InspectorFrontendAPI is initialized.
         this._dispatchOnInspectorFrontendAPI('addExtensions', [extensions]);
+      }
     }
 
     /**
      * @param {string} url
      */
     appendedToURL(url) {
       this._dispatchOnInspectorFrontendAPI('appendedToURL', [url]);
     }
 
     /**
@@ skipping 1173 matching lines @@
      * @return {boolean}
      */
     DOMTokenList.prototype.toggle = function(token, force) {
       if (arguments.length === 1)
         force = !this.contains(token);
       return this.__originalDOMTokenListToggle(token, !!force);
     };
   }
 
 })(window);