910e7b04fb
The primary problem was that on some browsers the state change doesn't take effect until the popState event has been called, so I added a check for that. Also added a support flag for IE9. BUG= Review URL: https://codereview.chromium.org//11697011 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@16562 260f80e4-7a28-3924-810f-c04153c831b5