Canonicalize the authenticated username on iOS.

Canonicalize the authenticated username on iOS.

The account reconcilor uses the canonicalized emails to look up accounts
in the ProfileOAuth2TokenService.
This CL canonicalizes the authenticated username when the sign-in manager
initializes for backward compability.

TEST=Also regression test to check that nothing breaks for pre-SSO signed
in users.

BUG=394355
Committed: https://crrev.com/6458afea246f5f7dd2b7f4f3e3f55a7c109b6b75
Cr-Commit-Position: refs/heads/master@{#295055}

[msarda, 2014-07-22 13:26:36]

Please take a look.

[Roger Tawa OOO till Jul 10th, 2014-07-28 14:11:01]

lgtm

[msarda, 2014-09-16 12:47:41]

The CQ bit was checked by msarda@chromium.org

[commit-bot: I haz the power, 2014-09-16 12:48:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/413453002/1

[commit-bot: I haz the power, 2014-09-16 13:47:05]

Committed patchset #1 (id:1) as 11878a9da2ebedb13ccf51a0dc6f85967e428fbd

[commit-bot: I haz the power, 2014-09-16 13:48:28]

Patchset 1 (id:??) landed as
https://crrev.com/6458afea246f5f7dd2b7f4f3e3f55a7c109b6b75
Cr-Commit-Position: refs/heads/master@{#295055}