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

third_party/WebKit/Source/devtools/front_end/resources/DatabaseModel.js

 /*
  * Copyright (C) 2007, 2008 Apple 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 128 matching lines @@
  */
 WebInspector.DatabaseModel = function(target)
 {
     WebInspector.SDKModel.call(this, WebInspector.DatabaseModel, target);
 
     this._databases = [];
     this._agent = target.databaseAgent();
     this.target().registerDatabaseDispatcher(new WebInspector.DatabaseDispatcher(this));
 }
 
+/** @enum {symbol} */
 WebInspector.DatabaseModel.Events = {
-    DatabaseAdded: "DatabaseAdded",
-    DatabasesRemoved: "DatabasesRemoved"
+    DatabaseAdded: Symbol("DatabaseAdded"),
+    DatabasesRemoved: Symbol("DatabasesRemoved")
 }
 
 WebInspector.DatabaseModel.prototype = {
     enable: function()
     {
         if (this._enabled)
             return;
         this._agent.enable();
         this._enabled = true;
     },
@@ skipping 62 matching lines @@
  * @param {!WebInspector.Target} target
  * @return {!WebInspector.DatabaseModel}
  */
 WebInspector.DatabaseModel.fromTarget = function(target)
 {
     if (!target[WebInspector.DatabaseModel._symbol])
         target[WebInspector.DatabaseModel._symbol] = new WebInspector.DatabaseModel(target);
 
     return target[WebInspector.DatabaseModel._symbol];
 }