Reenable MediaGalleriesPlatformAppBrowserTest.MediaGalleriesRead test.

Reenable MediaGalleriesPlatformAppBrowserTest.MediaGalleriesRead test.

It's no longer flaky since the underlying bug was fixed in crrev.com/615633003.

BUG=415792
Committed: https://crrev.com/5689fdb4d43581749d0071e5dbf417b782424520
Cr-Commit-Position: refs/heads/master@{#297764}

[Oren Blasberg, 2014-09-30 16:47:42]

orenb@chromium.org changed reviewers:
+ tommycli@chromium.org

[Oren Blasberg, 2014-09-30 16:48:25]

I won't commit this until the bug fix is committed too. Just wanted to get this
cl ready.

[Oren Blasberg, 2014-09-30 18:55:03]

Bug fix got committed so this should be ok now.

[tommycli, 2014-10-01 21:56:25]

LGTM

[Oren Blasberg, 2014-10-01 21:57:29]

The CQ bit was checked by orenb@chromium.org

[commit-bot: I haz the power, 2014-10-01 21:58:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/619683002/1

[commit-bot: I haz the power, 2014-10-02 00:07:08]

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

[commit-bot: I haz the power, 2014-10-02 00:07:09]

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

[Oren Blasberg, 2014-10-02 00:22:25]

The CQ bit was checked by orenb@chromium.org

[commit-bot: I haz the power, 2014-10-02 00:24:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/619683002/1

[commit-bot: I haz the power, 2014-10-02 02:01:34]

Committed patchset #1 (id:1) as 69059e6100978c6cd186cc58814a3044ba12615e

[commit-bot: I haz the power, 2014-10-02 02:02:29]

Patchset 1 (id:??) landed as
https://crrev.com/5689fdb4d43581749d0071e5dbf417b782424520
Cr-Commit-Position: refs/heads/master@{#297764}