remove 'GPrefs' from Svc, Preferences will do fine; don't make the username in the center status a link, since the whole area is a click target; open 'generic dialogs' for change password & passphrase

services/sync/modules/service.js

@@ -596,10 +596,8 @@ WeaveSvc.prototype = {
 
   changePassword: function WeaveSvc_changePassword(newpass)
     this._catch(this._notify("changepwd", "", function() {
-      let url = this.baseURL + '1/' + username + "/password";
+      let url = this.baseURL + '1/' + this.username + "/password";
       let res = new Weave.Resource(url);
-      res.authenticator = new Weave.NoOpAuthenticator();
-
       let resp = res.post(newpass);
       if (resp.status != 200) {
         this._log.info("Password change failed: " + resp);

services/sync/modules/util.js

@@ -788,7 +788,6 @@ Utils.EventListener.prototype = {
 
 let Svc = {};
 Svc.Prefs = new Preferences(PREFS_BRANCH);
-Svc.GPrefs = new Preferences();
 [["Annos", "@mozilla.org/browser/annotation-service;1", "nsIAnnotationService"],
  ["AppInfo", "@mozilla.org/xre/app-info;1", "nsIXULAppInfo"],
  ["Bookmark", "@mozilla.org/browser/nav-bookmarks-service;1", "nsINavBookmarksService"],