tree d3660f3d5b612efe5cfb9216636dc688fef12a6e
parent 17f8d2089d2262817e49b7e627e47bfeba163b98
author Natalie Weizenbaum <nweiz@google.com> 1462920137 -0700
committer Natalie Weizenbaum <nweiz@google.com> 1462920137 -0700

Add type-coercion functions.

These match (and are based on) the coercion functions in
dart-lang/async.

R=sigmund@google.com

Review URL: https://codereview.chromium.org//1966853003 .