DevTools: do not allow using 'this' before call into super.

third_party/WebKit/Source/devtools/front_end/source_frame/ResourceSourceFrame.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) IBM Corp. 2009  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 16 matching lines @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /**
  * @extends {WebInspector.SourceFrame}
  * @constructor
  * @param {!WebInspector.ContentProvider} resource
  */
 WebInspector.ResourceSourceFrame = function(resource)
 {
+    WebInspector.SourceFrame.call(this, resource.contentURL(), resource.requestContent.bind(resource));
     this._resource = resource;
-    WebInspector.SourceFrame.call(this, resource.contentURL(), resource.requestContent.bind(resource));
 };
 
 /**
  * @param {!WebInspector.ContentProvider} resource
  * @param {string} highlighterType
  * @return {!WebInspector.SearchableView}
  */
 WebInspector.ResourceSourceFrame.createSearchableView = function(resource, highlighterType)
 {
     var sourceFrame = new WebInspector.ResourceSourceFrame(resource);
@@ skipping 19 matching lines @@
      * @return {!Promise}
      */
     populateTextAreaContextMenu: function(contextMenu, lineNumber, columnNumber)
     {
         contextMenu.appendApplicableItems(this._resource);
         return Promise.resolve();
     },
 
     __proto__: WebInspector.SourceFrame.prototype
 };