Fix an issue with configuring the severity of lints.

Fix an issue with configuring the severity of lints.

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

Committed: https://github.com/dart-lang/sdk/commit/796baf6f165a9926333461834665766df1405504

[devoncarew, 2017-05-04 22:53:11]

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

[devoncarew, 2017-05-04 22:53:11]

Fix https://github.com/dart-lang/sdk/issues/29563 - an issue with configuring
the severity of lints.

It looks like regular error codes use uppercase and lint code use lowercase. Not
clear what all the impact would be of normalizing them all to one case or the
other.

[Brian Wilkerson, 2017-05-04 23:43:23]

lgtm

Do we require the upper case version of error codes to be in the analysis
options file? I thought we were basically treating them as being case
insensitive. (Same for codes in "//ignore" comments.)

[devoncarew, 2017-05-05 03:57:05]

We normalize everything to uppercase (at least for the purposes of of
ErrorProcessor). There's definitely some inconsistency. We generally to checks
based on normalized-to-uppercase, but we display in lower-case.

Personally I think lowercase is more esthetic. I was concerned about normalizing
one way or another in this CL, other checks that might fail, and any
implications for summary files.

[pquitslund, 2017-05-05 19:30:43]

lgtm

[devoncarew, 2017-05-05 20:17:08]

Description was changed from

==========
Fix an issue with configuring the severity of lints.

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

to

==========
Fix an issue with configuring the severity of lints.

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

Committed:
https://github.com/dart-lang/sdk/commit/796baf6f165a9926333461834665766df1405504
==========

[devoncarew, 2017-05-05 20:17:10]

Committed patchset #2 (id:20001) manually as
796baf6f165a9926333461834665766df1405504 (presubmit successful).