tree 3ca6442fe2de517527660f5707d99e247960f400
parent 4bfe9f9fc0b9dfe3b955d173513f69fee0212088
author nweiz@google.com <nweiz@google.com> 1400703952 +0000
committer nweiz@google.com <nweiz@google.com> 1400703952 +0000

Add MapKeySet and MapValueSet to the collection package.

These classes provide Set views that are implemented as Maps under the
covers.

BUG=18705
R=floitsch@google.com, lrn@google.com

Review URL: https://codereview.chromium.org//277563007

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/collection@36447 260f80e4-7a28-3924-810f-c04153c831b5