Enable ExtensionApiTest.MessagingUserGesture test.

Enable ExtensionApiTest.MessagingUserGesture test

This test was disabled temporarily while changing how the fake
UserGestureIndicator is set for tests.

Depends on blink patch:
https://codereview.chromium.org/518633002/

BUG=408426, 406336

[Zeeshan Qureshi, 2014-09-03 21:26:11]

zeeshanq@chromium.org changed reviewers:
+ jochen@chromium.org

[Zeeshan Qureshi, 2014-09-03 21:26:12]

+jochen PTAL.

I disabled this test in https://codereview.chromium.org/518633002/ as blink will
be creating 2 fake UGIs until https://codereview.chromium.org/518633002/ lands.

[Zeeshan Qureshi, 2014-09-03 21:27:07]

correction:

The test was disabled in https://codereview.chromium.org/518583003/

[jochen (gone - plz use gerrit), 2014-09-04 09:42:06]

lgtm

[Zeeshan Qureshi, 2014-09-10 00:08:57]

The CQ bit was checked by zeeshanq@chromium.org

[commit-bot: I haz the power, 2014-09-10 00:14:26]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/zeeshanq@chromium.org/521743002/1

[Zeeshan Qureshi, 2014-09-10 01:32:16]

The CQ bit was unchecked by zeeshanq@chromium.org

[Zeeshan Qureshi, 2014-09-10 01:34:59]

The CQ bit was checked by zeeshanq@chromium.org

[Zeeshan Qureshi, 2014-09-10 01:38:50]

The CQ bit was unchecked by zeeshanq@chromium.org

[commit-bot: I haz the power, 2014-09-10 01:42:02]

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

[Zeeshan Qureshi, 2014-09-10 01:47:05]

Patchset #2 (id:20001) has been deleted

[Zeeshan Qureshi, 2014-09-10 01:50:05]

Patchset #2 (id:40001) has been deleted