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

third_party/WebKit/Source/devtools/front_end/ui/Context.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.Context = function()
 {
     this._flavors = new Map();
     this._eventDispatchers = new Map();
 }
 
-/**
- * @enum {string}
- */
+/** @enum {symbol} */
 WebInspector.Context.Events = {
-    FlavorChanged: "FlavorChanged"
+    FlavorChanged: Symbol("FlavorChanged")
 }
 
 WebInspector.Context.prototype = {
     /**
      * @param {function(new:T, ...)} flavorType
      * @param {?T} flavorValue
      * @template T
      */
     setFlavor: function(flavorType, flavorValue)
     {
@@ skipping 97 matching lines @@
 WebInspector.ContextFlavorListener = function() { }
 
 WebInspector.ContextFlavorListener.prototype = {
     /**
      * @param {?Object} object
      */
     flavorChanged: function(object) { }
 }
 
 WebInspector.context = new WebInspector.Context();