DevTools: fix disposing of main debugger script mappings

third_party/WebKit/Source/devtools/front_end/snippets/ScriptSnippetModel.js

 /*
  * Copyright (C) 2012 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 37 matching lines @@
     this._lastSnippetEvaluationIndexSetting = WebInspector.settings.createSetting("lastSnippetEvaluationIndex", 0);
     this._project = new WebInspector.SnippetsProject(workspace, this);
     this._loadSnippets();
     WebInspector.targetManager.observeTargets(this);
 }
 
 WebInspector.ScriptSnippetModel.snippetSourceURLPrefix = "snippets:///";
 
 
 WebInspector.ScriptSnippetModel.prototype = {
-
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetAdded: function(target)
     {
         var debuggerModel = WebInspector.DebuggerModel.fromTarget(target);
         if (debuggerModel)
             this._mappingForTarget.set(target, new WebInspector.SnippetScriptMapping(debuggerModel, this));
     },
@@ skipping 600 matching lines @@
         this._model.deleteScriptSnippet(url);
     },
 
     __proto__: WebInspector.ContentProviderBasedProject.prototype
 }
 
 /**
  * @type {!WebInspector.ScriptSnippetModel}
  */
 WebInspector.scriptSnippetModel = new WebInspector.ScriptSnippetModel(WebInspector.workspace);