Default trailing comma support to `true` (#26647).

Default trailing comma support to `true` (#26647).

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

See: https://github.com/dart-lang/sdk/issues/26647.
Committed: https://github.com/dart-lang/sdk/commit/722d4a13b04c7b4f1d021c7157380d758c9f9a43

[pquitslund, 2016-07-26 22:28:30]

pquitslund@google.com changed reviewers:
+ brianwilkerson@google.com, scheglov@google.com

[pquitslund, 2016-07-26 22:30:34]

On 2016/07/26 22:28:31, pquitslund wrote:

Incidentally, you may wonder why this is completely removing the flag.  Well, as
it turns out it was only partly working as there are a number of places that
Parsers are created where the option didn't propagate.  I figured just removing
it was the best approach.  Let me know if you think otherwise!

[scheglov, 2016-07-27 00:46:04]

lgtm

[Brian Wilkerson, 2016-07-27 15:07:47]

Are trailing commas supported everywhere? If not, it seems like we ought to
wait, otherwise analyzer won't give a warning for code that won't work anywhere
other than DDC.

[pquitslund, 2016-07-27 16:16:46]

On 2016/07/27 15:07:47, Brian Wilkerson wrote:
> Are trailing commas supported everywhere? If not, it seems like we ought to
> wait, otherwise analyzer won't give a warning for code that won't work
anywhere
> other than DDC.

Only the formatter and style guide are lagging behind so I think we're good to
go.

[Brian Wilkerson, 2016-07-27 16:19:02]

In that case, lgtm.

[pquitslund, 2016-07-27 16:42:18]

Description was changed from

==========
Default trailing comma support to `true` (#26647).

BUG=

See: https://github.com/dart-lang/sdk/issues/26647.
==========

to

==========
Default trailing comma support to `true` (#26647).

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

See: https://github.com/dart-lang/sdk/issues/26647.
Committed:
https://github.com/dart-lang/sdk/commit/722d4a13b04c7b4f1d021c7157380d758c9f9a43
==========

[pquitslund, 2016-07-27 16:42:20]

Committed patchset #1 (id:1) manually as
722d4a13b04c7b4f1d021c7157380d758c9f9a43 (presubmit successful).