DevTools: [Sources] sourcesNavigator should not rely on existance of main target

third_party/WebKit/Source/devtools/front_end/sources/SourcesNavigator.js

 /*
  * Copyright (C) 2011 Google Inc. 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 41 matching lines @@
     /**
      * @param {!WebInspector.Event} event
      */
     _inspectedURLChanged: function(event)
     {
         var mainTarget = WebInspector.targetManager.mainTarget();
         if (event.data !== mainTarget)
             return;
         var inspectedURL = mainTarget && mainTarget.inspectedURL();
         if (!inspectedURL)
-            return
+            return;
         for (var node of this._uiSourceCodeNodes.valuesArray()) {
             var uiSourceCode = node.uiSourceCode();
             if (uiSourceCode.url() === inspectedURL)
                 this.revealUISourceCode(uiSourceCode, true);
         }
     },
 
     /**
      * @override
      * @param {!WebInspector.UISourceCode} uiSourceCode
      */
     uiSourceCodeAdded: function(uiSourceCode)
     {
-        var inspectedPageURL = WebInspector.targetManager.mainTarget().inspectedURL();
-        if (uiSourceCode.url() === inspectedPageURL)
+        var mainTarget = WebInspector.targetManager.mainTarget();
+        var inspectedURL = mainTarget && mainTarget.inspectedURL();
+        if (!inspectedURL)
+            return;
+        if (uiSourceCode.url() === inspectedURL)
             this.revealUISourceCode(uiSourceCode, true);
     },
 
     /**
      * @override
      * @param {!Event} event
      */
     handleContextMenu: function(event)
     {
         var contextMenu = new WebInspector.ContextMenu(event);
@@ skipping 42 matching lines @@
                 this.revealUISourceCode(uiSourceCode, true);
         }
     },
 
     /**
      * @override
      * @param {!WebInspector.UISourceCode} uiSourceCode
      */
     uiSourceCodeAdded: function(uiSourceCode)
     {
-        var inspectedPageURL = WebInspector.targetManager.mainTarget().inspectedURL();
-        if (uiSourceCode.url() === inspectedPageURL)
+        var mainTarget = WebInspector.targetManager.mainTarget();
+        var inspectedURL = mainTarget && mainTarget.inspectedURL();
+        if (!inspectedURL)
+            return;
+        if (uiSourceCode.url() === inspectedURL)
             this.revealUISourceCode(uiSourceCode, true);
     },
 
     __proto__: WebInspector.NavigatorView.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.NavigatorView}
  */
@@ skipping 138 matching lines @@
     /**
      * @override
      */
     sourceDeleted: function(uiSourceCode)
     {
         this._handleRemoveSnippet(uiSourceCode);
     },
 
     __proto__: WebInspector.NavigatorView.prototype
 }