Add @assertFailingTest annotation support.

Add @assertFailingTest annotation support.

R=brianwilkerson@google.com, paulberry@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/e9109cd05f45194dce20e524bf35f7c4ccb25677

[Brian Wilkerson, 2016-04-29 16:31:51]

lgtm

[Paul Berry, 2016-04-29 17:57:31]

lgtm

https://codereview.chromium.org/1933283002/diff/1/pkg/analyzer/test/reflectiv...
File pkg/analyzer/test/reflective_tests.dart (right):

https://codereview.chromium.org/1933283002/diff/1/pkg/analyzer/test/reflectiv...
pkg/analyzer/test/reflective_tests.dart:32: * Is `true` the application runs in
the checked mode.
s/runs/is running/

("runs" implies that the app "normally runs" in checked mode, or "is able to
run" in checked mode; "is running" refers to the state of the current run)

[scheglov, 2016-04-29 18:04:07]

https://codereview.chromium.org/1933283002/diff/1/pkg/analyzer/test/reflectiv...
File pkg/analyzer/test/reflective_tests.dart (right):

https://codereview.chromium.org/1933283002/diff/1/pkg/analyzer/test/reflectiv...
pkg/analyzer/test/reflective_tests.dart:32: * Is `true` the application runs in
the checked mode.
On 2016/04/29 17:57:31, Paul Berry wrote:
> s/runs/is running/
> 
> ("runs" implies that the app "normally runs" in checked mode, or "is able to
> run" in checked mode; "is running" refers to the state of the current run)

Done.
Thanks!

[scheglov, 2016-04-29 18:04:22]

Description was changed from

==========
Add @assertFailingTest annotation support.

R=brianwilkerson@google.com, paulberry@google.com
BUG=
==========

to

==========
Add @assertFailingTest annotation support.

R=brianwilkerson@google.com, paulberry@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/e9109cd05f45194dce20e524bf35f7c4ccb25677
==========

[scheglov, 2016-04-29 18:04:24]

Committed patchset #1 (id:1) manually as
e9109cd05f45194dce20e524bf35f7c4ccb25677 (presubmit successful).

[eernst, 2016-05-02 09:11:43]

On 2016/04/29 18:04:24, scheglov wrote:
> Committed patchset #1 (id:1) manually as
> e9109cd05f45194dce20e524bf35f7c4ccb25677 (presubmit successful).

Hello Konstantin,

I reverted the removal of the `MirrorsUsed` annotation because my
CL got blamed for failures on dart2js-jsshell, but my experiments
show that it is this removal that makes the difference. I guess that
you would want to keep it (because tests run for 5-6 times longer in
the dart2js-jsshell columns without it), or alternatively you'd want
to mark a lot of tests as `slow` in the relevant status files.

I realize that there may be a need to add `_FailingTest` and 
`_AssertFailingTest` to the `MirrorsUsed` annotation, but I wanted to
make the smallest possible change that would still allow me to land
CL 1915123008 in good shape, so I just reinserted the old
`MirrorsUsed`, such that those timeouts go away.