[css-flexbox] Make min-size:auto work correctly with an explicit width on the flex item

[css-flexbox] Make min-size:auto work correctly with an explicit width on the flex item

This was a silly typo in the original change (https://codereview.chromium.org/1421423005)

Found by running the CSSWG test suite. Adding the test that found it until we import the
full suite.

R=leviw@chromium.org
BUG=546034
Committed: https://crrev.com/e07c0a227e36b4fefbf0927633c404f2606a4ed4
Cr-Commit-Position: refs/heads/master@{#357004}

[cbiesinger, 2015-10-29 20:40:21]

The CQ bit was checked by cbiesinger@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-10-29 20:41:21]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1420283011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1420283011/1

[leviw_travelin_and_unemployed, 2015-10-29 20:48:05]

D'oh! Thanks, Christian.

LGTM.

[cbiesinger, 2015-10-29 20:48:45]

The CQ bit was unchecked by cbiesinger@chromium.org

[cbiesinger, 2015-10-29 20:48:49]

The CQ bit was checked by cbiesinger@chromium.org

[commit-bot: I haz the power, 2015-10-29 20:49:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1420283011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1420283011/1

[commit-bot: I haz the power, 2015-10-29 22:58:07]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-10-29 22:58:07]

Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[cbiesinger1, 2015-10-29 23:58:30]

The CQ bit was checked by cbiesinger@google.com

[commit-bot: I haz the power, 2015-10-29 23:58:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1420283011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1420283011/1

[commit-bot: I haz the power, 2015-10-30 00:53:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-30 00:54:37]

Patchset 1 (id:??) landed as
https://crrev.com/e07c0a227e36b4fefbf0927633c404f2606a4ed4
Cr-Commit-Position: refs/heads/master@{#357004}