Merge 98454 - Web Inspector: Debugger fails when there is an invalid watch expression.

Source/WebCore/inspector/front-end/ScriptsPanel.js

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 449 matching lines @@
         function didEvaluate(result, wasThrown)
         {
             if (objectGroup === "console")
                 this.sidebarPanes.scopechain.update(this._presentationModel.selectedCallFrame);
             if (returnByValue)
                 callback(null, wasThrown, wasThrown ? null : result);
             else
                 callback(WebInspector.RemoteObject.fromPayload(result), wasThrown);
         }
         var selectedCallFrame = this._presentationModel.selectedCallFrame;
-        selectedCallFrame.evaluate(code, objectGroup, includeCommandLineAPI, returnByValue, didEvaluate.bind(this));
+        if (selectedCallFrame)
+            selectedCallFrame.evaluate(code, objectGroup, includeCommandLineAPI, returnByValue, didEvaluate.bind(this));
     },
 
     getSelectedCallFrameVariables: function(callback)
     {
         var result = { this: true };
 
         var selectedCallFrame = this._presentationModel.selectedCallFrame;
         if (!selectedCallFrame)
             callback(result);
 
@@ skipping 809 matching lines @@
     },
 
     suggestedFileName: function()
     {
         var names = this._scriptsPanel._folderAndDisplayNameForScriptURL(this._uiSourceCode.url);
         return names.displayName || "untitled.js";
     }
 }
 
 WebInspector.SourceFrameDelegateForScriptsPanel.prototype.__proto__ = WebInspector.SourceFrameDelegate.prototype;