Add //components/signin/ios/browser:unit_tests to components_unittests.

Add //components/signin/ios/browser:unit_tests to components_unittests.

Fix an incorrect dependency in the BUILD.gn file and add deps to
the targets in //components/BUILD.gn.

Add a reference to gn target in //components/sessions.gypi.

BUG=459705
Committed: https://crrev.com/06332e60d4928fee0cfa695cd55b3eab8f31a26a
Cr-Commit-Position: refs/heads/master@{#360320}

[sdefresne, 2015-11-13 17:38:06]

sdefresne@chromium.org changed reviewers:
+ dpranke@chromium.org

[sdefresne, 2015-11-13 17:38:06]

Please take a look.

[Dirk Pranke, 2015-11-13 17:43:08]

lgtm

[sdefresne, 2015-11-17 16:23:44]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2015-11-17 16:24:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1441353003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1441353003/1

[commit-bot: I haz the power, 2015-11-17 16:27:24]

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

[commit-bot: I haz the power, 2015-11-17 16:27:24]

Try jobs failed on following builders:
  ios_dbg_simulator_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[sdefresne, 2015-11-18 09:45:11]

The CQ bit was checked by sdefresne@chromium.org

[sdefresne, 2015-11-18 09:45:11]

The patchset sent to the CQ was uploaded after l-g-t-m from dpranke@chromium.org
Link to the patchset: https://codereview.chromium.org/1441353003/#ps20001
(title: "Rebase")

[commit-bot: I haz the power, 2015-11-18 09:45:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1441353003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1441353003/20001

[commit-bot: I haz the power, 2015-11-18 10:54:05]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-18 10:55:11]

Patchset 2 (id:??) landed as
https://crrev.com/06332e60d4928fee0cfa695cd55b3eab8f31a26a
Cr-Commit-Position: refs/heads/master@{#360320}

[miu, 2015-11-19 02:50:47]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1458603009/ by miu@chromium.org.

The reason for reverting is: This patch set very likely broke all the
tab_capture_end2end_tests on Mac.

I am reverting this AND the change the sheriff made (which disabled the failing
tests): https://codereview.chromium.org/1456863003/

See http://crbug.com/557929 for more details..