[DevTools] Make resource tree model optional

third_party/WebKit/Source/devtools/front_end/resources/ClearStorageView.js

 // Copyright (c) 2016 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.
 
 /**
  * @constructor
  * @extends {WebInspector.VBox}
  * @implements {WebInspector.TargetManager.Observer}
  * @param {!WebInspector.ResourcesPanel} resourcesPanel
  */
@@ skipping 52 matching lines @@
 
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetAdded: function(target)
     {
         if (this._target)
             return;
         this._target = target;
-        this._updateOrigin(target.resourceTreeModel.mainFrame ? target.resourceTreeModel.mainFrame.url : "");
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(target);
+        this._updateOrigin((resourceTreeModel && resourceTreeModel.mainFrame) ? resourceTreeModel.mainFrame.url : "");
         WebInspector.targetManager.addEventListener(WebInspector.TargetManager.Events.MainFrameNavigated, this._updateFrame, this);
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _updateFrame: function(event)
     {
         var frame = /** *@type {!WebInspector.ResourceTreeFrame} */ (event.data);
         this._updateOrigin(frame.url);
@@ skipping 71 matching lines @@
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
     },
 
     __proto__: WebInspector.VBox.prototype
 }