[DevTools] Improve context and target naming.

third_party/WebKit/Source/devtools/front_end/sdk/ResourceTreeModel.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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 705 matching lines @@
       if (this._childFrames[i]._callForFrameResources(callback))
         return true;
     }
     return false;
   }
 
   /**
    * @return {string}
    */
   displayName() {
-    if (!this._parentFrame)
+    if (!this._parentFrame && !this._model.target().parentTarget())
       return Common.UIString('top');
     var subtitle = new Common.ParsedURL(this._url).displayName;
     if (subtitle) {
       if (!this._name)
         return subtitle;
       return this._name + ' (' + subtitle + ')';
     }
     return Common.UIString('<iframe>');
   }
 };
@@ skipping 146 matching lines @@
     this._resourceTreeModel.dispatchEventToListeners(SDK.ResourceTreeModel.Events.InterstitialHidden);
   }
 
   /**
    * @override
    */
   navigationRequested() {
     // Frontend is not interested in when navigations are requested.
   }
 };