[DevTools] Explicitly require ResourceTreeModel

third_party/WebKit/Source/devtools/front_end/sdk/CSSStyleSheetHeader.js

 // Copyright 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
  * @implements {WebInspector.ContentProvider}
  * @param {!WebInspector.CSSModel} cssModel
  * @param {!CSSAgent.CSSStyleSheetHeader} payload
  */
@@ skipping 59 matching lines @@
     resourceURL: function()
     {
         return this.isViaInspector() ? this._viaInspectorResourceURL() : this.sourceURL;
     },
 
     /**
      * @return {string}
      */
     _viaInspectorResourceURL: function()
     {
-        var frame = this._cssModel.target().resourceTreeModel.frameForId(this.frameId);
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this.target());
+        var frame = resourceTreeModel.frameForId(this.frameId);
         console.assert(frame);
         var parsedURL = new WebInspector.ParsedURL(frame.url);
         var fakeURL = "inspector://" + parsedURL.host + parsedURL.folderPathComponents;
         if (!fakeURL.endsWith("/"))
             fakeURL += "/";
         fakeURL += "inspector-stylesheet";
         return fakeURL;
     },
 
     /**
@@ skipping 121 matching lines @@
          */
         function performSearch(content)
         {
             var searchResults = content ? WebInspector.ContentProvider.performSearchInContent(content, query, caseSensitive, isRegex) : [];
             callback(searchResults);
         }
 
         this.requestContent().then(performSearch);
     }
 }