Handle multipart MIME parsing with no parts

The multipart MIME parser did not correctly handle the case where there
was only the final boundary.

R=kustermann@google.com
BUG=

Review URL: https://codereview.chromium.org//739533002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/mime@41805 260f80e4-7a28-3924-810f-c04153c831b5
4 files changed
tree: 995ea0a7352f1c7ae751b284e89f5573b434f0d8
  1. lib/
  2. test/
  3. CHANGELOG.md
  4. LICENSE
  5. pubspec.yaml