DevTools: Use JS symbols instead of strings for eligible events.

third_party/WebKit/Source/devtools/front_end/sdk/DOMModel.js

 /*
  * Copyright (C) 2009, 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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.
@@ skipping 1094 matching lines @@
     target.registerDOMDispatcher(new WebInspector.DOMDispatcher(this));
 
     this._inspectModeEnabled = false;
 
     this._defaultHighlighter = new WebInspector.DefaultDOMNodeHighlighter(this._agent);
     this._highlighter = this._defaultHighlighter;
 
     this._agent.enable();
 }
 
+/** @enum {string} */
 WebInspector.DOMModel.Events = {
     AttrModified: "AttrModified",
     AttrRemoved: "AttrRemoved",
     CharacterDataModified: "CharacterDataModified",
     DOMMutated: "DOMMutated",
     NodeInserted: "NodeInserted",
     NodeInspected: "NodeInspected",
     NodeHighlightedInOverlay: "NodeHighlightedInOverlay",
     NodeRemoved: "NodeRemoved",
     DocumentUpdated: "DocumentUpdated",
     ChildNodeCountUpdated: "ChildNodeCountUpdated",
     UndoRedoRequested: "UndoRedoRequested",
     UndoRedoCompleted: "UndoRedoCompleted",
     DistributedNodesChanged: "DistributedNodesChanged",
     ModelSuspended: "ModelSuspended",
     InspectModeWillBeToggled: "InspectModeWillBeToggled",
     MarkersChanged: "MarkersChanged"
 }
 
-
 /**
  * @param {!WebInspector.RemoteObject} object
  */
 WebInspector.DOMModel.highlightObjectAsDOMNode = function(object)
 {
     var domModel = WebInspector.DOMModel.fromTarget(object.target());
     if (domModel)
         domModel.highlightDOMNode(undefined, undefined, undefined, object.objectId);
 }
 
@@ skipping 1135 matching lines @@
 }
 
 /**
  * @param {!WebInspector.Target} target
  * @return {?WebInspector.DOMModel}
  */
 WebInspector.DOMModel.fromTarget = function(target)
 {
     return /** @type {?WebInspector.DOMModel} */ (target.model(WebInspector.DOMModel));
 }