Fix pkg:http tests to include the accept-encoding header.

BUG=

Review URL: https://codereview.chromium.org//13937008

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/http@21135 260f80e4-7a28-3924-810f-c04153c831b5
3 files changed
tree: a9c745763d4f00343d7e0a52a4d43db7543a2b9a
  1. lib/
  2. test/
  3. pubspec.yaml