nsIWebBrowserChrome2 in Firefox 3.6a1pre

 Called when the status text in the chrome needs to be updated.  This
 method may be called instead of nsIWebBrowserChrome::SetStatus.  An
 implementor of this method, should still implement SetStatus.

 @param statusType
        Indicates what is setting the text.
 @param status
        Status string.  Null is an acceptable value meaning no status.
 @param contextNode 
        An object that provides context pertaining to the status type.
        If statusType is STATUS_LINK, then statusContext may be a DOM
        node corresponding to the source of the link.  This value can
        be null if there is no context.