Fixes a bug in DOMImplTrident#getTagName() where it does not handle an undefined scope name.

Patch by: kerjin2001   	
Review by: jlabanca



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@6081 8db76d5a-ed1c-0410-87a9-c151d255dfc7