Fixes a sporadic RunStyleSelenium bug caused by not properly waiting for the URL to load before checking the title of the page.  Also adds a thread lock to ensure that we don't get harmless but visible errors in the selenium console.
http://gwt-code-reviews.appspot.com/264801/show

Review by: mmendez@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7789 8db76d5a-ed1c-0410-87a9-c151d255dfc7