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

third_party/WebKit/Source/devtools/front_end/ui/ActionRegistry.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  */
 WebInspector.ActionRegistry = function()
 {
     /** @type {!Map.<string, !WebInspector.Action>} */
@@ skipping 69 matching lines @@
  * @param {!Runtime.Extension} extension
  */
 WebInspector.Action = function(extension)
 {
     WebInspector.Object.call(this);
     this._extension = extension;
     this._enabled = true;
     this._toggled = false;
 }
 
+/** @enum {symbol} */
 WebInspector.Action.Events = {
-    Enabled: "Enabled",
-    Toggled: "Toggled"
+    Enabled: Symbol("Enabled"),
+    Toggled: Symbol("Toggled")
 }
 
 WebInspector.Action.prototype = {
     /**
      * @return {string}
      */
     id: function()
     {
         return this._extension.descriptor()["actionId"];
     },
@@ skipping 112 matching lines @@
     /**
      * @param {!WebInspector.Context} context
      * @param {string} actionId
      * @return {boolean}
      */
     handleAction: function(context, actionId) {}
 }
 
 /** @type {!WebInspector.ActionRegistry} */
 WebInspector.actionRegistry;