add: pbi.addObserver(PREF_UPDATE_APP_INTERVAL, this, false); pbi.addObserver(PREF_UPDATE_EXTENSIONS_INTERVAL, this, false); 
context: function nsUpdateService(){  this._pref = Components.classes["@mozilla.org/preferences-service;1"]                         .getService(Components.interfaces.nsIPrefBranch);  this.watchForUpdates();  var pbi = this._pref.QueryInterface(Components.interfaces.nsIPrefBranchInternal);  pbi.addObserver(PREF_UPDATE_APP_ENABLED, this, false);  pbi.addObserver(PREF_UPDATE_EXTENSIONS_ENABLED, this, false);  pbi.addObserver(PREF_UPDATE_INTERVAL, this, false);  // Observe xpcom-shutdown to unhook pref branch observers above to avoid   // shutdown leaks.  var os = Components.classes["@mozilla.org/observer-service;1"]                     .getService(Components.interfaces.nsIObserverService);  os.addObserver(this, "xpcom-shutdown", false);}
meta: 7628	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/7628/7051d29a77ef2e0bc04610fb427f20ca78197995/nsBackgroundUpdateService.js/buggy/src/nsBackgroundUpdateService.js