Pass "client_id" param to the enrollment frame.

Pass "client_id" param to the enrollment frame.

A "client_id" param passed to GAIA should match a "client_id" that is used for
token exchange afterwards, otherwise token exchange doesn't work. If the param
is not specified, GAIA uses default value, which is the same as official Google
Chrome's "client_id".

We didn't provide "client_id" for enrollment frame, as a result enrollment only
worked in official builds.

BUG=495527
TEST=browser_tests

Committed: https://crrev.com/54308302f2fe310fc34c14b01060d1561d3b5548
Cr-Commit-Position: refs/heads/master@{#342871}

[dzhioev (left Google), 2015-08-11 02:21:54]

dzhioev@chromium.org changed reviewers:
+ rogerta@chromium.org

[dzhioev (left Google), 2015-08-11 02:23:11]

Hello, PTAL

[Roger Tawa OOO till Jul 10th, 2015-08-11 14:43:53]

lgtm

[dzhioev (left Google), 2015-08-11 18:25:47]

The CQ bit was checked by dzhioev@chromium.org

[commit-bot: I haz the power, 2015-08-11 18:26:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1282393002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1282393002/1

[commit-bot: I haz the power, 2015-08-11 19:31:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-11 19:32:40]

Patchset 1 (id:??) landed as
https://crrev.com/54308302f2fe310fc34c14b01060d1561d3b5548
Cr-Commit-Position: refs/heads/master@{#342871}