Properly handle errors thrown in [Chain.capture]'s [onError] handler.

The Zone infrastructure apparently doesn't automatically pipe errors
to the parent Zone (issue 18134).

R=rnystrom@google.com
BUG=

Review URL: https://codereview.chromium.org//232123003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/stack_trace@34904 260f80e4-7a28-3924-810f-c04153c831b5
4 files changed
tree: 834f318172f594e1cd88c0326a142b9618a2298b
  1. pkgs/