Clean up http_multi_server.
Clean up http_multi_server.

BUG=
R=lrn@google.com

Review URL: https://codereview.chromium.org//597103002

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@40627 260f80e4-7a28-3924-810f-c04153c831b5

dart-lang/http_multi_server