TBR. Add back fix to the misleading types for onError. Otherwise, html/worker_test/functional fails…

TBR. Add back fix to the misleading types for onError. Otherwise, html/worker_test/functional fails due to the browser itself throwing an event of type Error that is not an ErrorEvent.

BUG=

Committed: https://github.com/dart-lang/sdk/commit/b546d0536205dbcf26726e7f74a3185ad941b058

[Jacob, 2016-04-20 17:41:46]

jacobr@google.com changed reviewers:
+ alanknight@google.com

[Jacob, 2016-04-20 17:41:46]

TBR

This fixes html/worker_test/functional which broke due to an unavoidable checked
mode check that the Event was an ErrorEvent.
The ErrorEvent was created by the browser not a user so this is not a case of
users intentionally lying about event types.

[Jacob, 2016-04-20 17:42:03]

Description was changed from

==========
TBR. Add back fix to the misleading types for onError. Otherwise,
html/worker_test/functional fails due to the browser itself throwing an event of
type Error that is not an ErrorEvent.

BUG=
==========

to

==========
TBR. Add back fix to the misleading types for onError. Otherwise,
html/worker_test/functional fails due to the browser itself throwing an event of
type Error that is not an ErrorEvent.

BUG=

Committed:
https://github.com/dart-lang/sdk/commit/b546d0536205dbcf26726e7f74a3185ad941b058
==========

[Jacob, 2016-04-20 17:42:04]

Committed patchset #1 (id:1) manually as
b546d0536205dbcf26726e7f74a3185ad941b058.

[Alan Knight, 2016-04-20 17:49:17]

lgtm