Revert of ChromeOS: fix user signin by alias.

Revert of ChromeOS: fix user signin by alias. (patchset #4 id:60001 of https://codereview.chromium.org/1370913002/ )

Reason for revert:
This Cl is causing the test login_OwnershipNotRetaken to fail on ChromePFQ. https://code.google.com/p/chromium/issues/detail?id=537986.

Original issue's description:
> THis CL fixes the issue with login using alternative e-mails.
>
> BUG=535369
> TEST=manual
>
> Committed: https://crrev.com/0f37b696b7a814d4157401c304643594a4ae9731
> Cr-Commit-Position: refs/heads/master@{#351482}

TBR=achuith@chromium.org,alemate@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=535369
Committed: https://crrev.com/98cd63d38fff2091a4ceda9130d93e41162bf1f5
Cr-Commit-Position: refs/heads/master@{#351886}

[afakhry, 2015-10-01 21:14:25]

Created Revert of ChromeOS: fix user signin by alias.

[commit-bot: I haz the power, 2015-10-01 21:15:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1384533003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1384533003/1

[commit-bot: I haz the power, 2015-10-01 21:17:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-01 21:19:13]

Patchset 1 (id:??) landed as
https://crrev.com/98cd63d38fff2091a4ceda9130d93e41162bf1f5
Cr-Commit-Position: refs/heads/master@{#351886}

[achuithb, 2015-10-01 21:23:18]

lgtm