Integrating nsIExtensionManager in xulrunner-1.9.2 with JavaXPCOM

Hi, all!
How to integrate and start the new version of interface
nsIExtensionManager for xulrunner-1.9.2 with JavaXPCOM?!
Someone would had the snippet code for that or some idea for that
implementation?
What changed between xulrunner-1.9.0 and xulrunner-1.9.2?
I executing the code:
nsIWindowWatcher winWatcher = XPCOMUtils.getService("@mozilla.org/
embedcomp/window-watcher;1", nsIWindowWatcher.class); //$NON-NLS-1$
                winWatcher.setWindowCreator(winCreator);
                nsIPrefBranch pref =
XPCOMUtils.getService("@mozilla.org/preferences-service;1",
nsIPrefBranch.class); //$NON-NLS-1$
                pref.setBoolPref("browser.download.useDownloadDir",
0); //$NON-NLS-1$
                //when page loading fails, display an error page,
                //similar as firefox does
                pref.setBoolPref("browser.xul.error_pages.enabled",
1); //$NON-NLS-1$
                //disable various security warning dialogs
                //such as when entering/leaving https site or
                //submitting form
                pref.setBoolPref("security.warn_entering_secure",
0); //$NON-NLS-1$
                pref.setBoolPref("security.warn_entering_weak",
0); //
$NON-NLS-1$
                pref.setBoolPref("security.warn_leaving_secure",
0); //
$NON-NLS-1$
                pref.setBoolPref("security.warn_submit_insecure",
0); //$NON-NLS-1$
                pref.setBoolPref("security.warn_viewing_mixed",
0); //
$NON-NLS-1$
                nsIExtensionManager em = getService("@mozilla.org/
extensions/manager;1", nsIExtensionManager.class); //$NON-NLS-1$
                                /**
                                * Returns XPCOM service with the given
contract ID. This method
                                * is an equivalent of the
<tt>do_GetService()</tt> macro in
mozilla
                                * source code. For example,
                                * <pre>
                                *   getService("@mozilla.org/
cookiemanager;1",
nsICookieManager.class)
                                * </pre>
                                * returns the <tt>nsICookieManager</
tt> interface of the Mozilla's
                                * cookie service. Similarly,
                                * <pre>
                                *   getService("@mozilla.org/
cookiemanager;1",
nsICookieService.class)
                                * </pre>
                                * returns the <tt>nsICookieService</
tt> interface of the cookie
service.
                                *
                                * @param <T> - an XPCOM interface
(org.mozilla.interfaces)
                                * @param contractID - identifier of
the XPCOM service
                                * @param c - interface of the XPCOM
service to be returned
                                * @return XPCOM service
                                */
                                public static <T extends nsISupports>
T getService(String
contractID, Class<T> c) {
                                try {
                                        Mozilla moz =
Mozilla.getInstance();
                                        String iid = guessIID(c);
                                        nsIServiceManager
serviceManager = moz.getServiceManager();
                                        T t = (T)
serviceManager.getServiceByContractID(contractID,
iid);
                                        return t;
                                } catch (Throwable e) {
                                        log.error("failed to create
XPCOM service", e); //$NON-NLS-1$
                                        return null;
                                }
                                }
and getting error:
                                GRAVE: failed to create XPCOM service
org.mozilla.xpcom.XPCOMException: The function
"getServiceByContractID" returned an error condition  (0x80570016)
                                at
org.mozilla.xpcom.internal.XPCOMJavaProxy.callXPCOMMethod(Native
Method)
                                at
org.mozilla.xpcom.internal.XPCOMJavaProxy.invoke(XPCOMJavaProxy.java:
143)
                                at
$Proxy0.getServiceByContractID(Unknown Source)
Thanks,
henson