[DevTools] Polyfill Object.observe for old frontends.

third_party/WebKit/Source/devtools/front_end/common/Settings.js

 /*
  * Copyright (C) 2009 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 248 matching lines @@
     get: function()
     {
         if (typeof this._value !== "undefined")
             return this._value;
 
         this._value = this._defaultValue;
         if (this._storage.has(this._name)) {
             try {
                 this._value = JSON.parse(this._storage.get(this._name));
             } catch(e) {
-                this.remove();
+                this._storage.remove(this._name);
             }
         }
         return this._value;
     },
 
     /**
      * @param {V} value
      */
     set: function(value)
     {
@@ skipping 466 matching lines @@
 }
 
 /**
  * @param {string} settingName
  * @return {!WebInspector.Setting}
  */
 WebInspector.settingForTest = function(settingName)
 {
     return WebInspector.settings.settingForTest(settingName);
 }