Revert of This CL replaces e-mail with AccountId on user selection screen.

Revert of This CL replaces e-mail with AccountId on user selection screen. (patchset #12 id:220001 of https://codereview.chromium.org/1440583002/ )

Reason for revert:
Suspecting this CL for introducing failures on Mac 10.10 Release (ATI)

First failure: https://build.chromium.org/p/chromium.gpu/builders/Mac%2010.10%20Release%20%28ATI%29/builds/8148

Failing tests:
CastStreamingApiTestWithPixelOutput.EndToEnd
TabCaptureApiPixelTest.EndToEndThroughWebRTC
TabCaptureApiPixelTest.EndToEndWithoutRemoting

Please update tests.

Original issue's description:
> This CL replaces e-mail with AccountId on user selection screen.
>
> This CL replaces e-mail with serialized AccountId on user selection screen.
> It also adds simple AccountId Serialize/Deserialize methods suitable for
> passing AccountId to JS code.
>
> This is part of transition to AccountId.
>
> BUG=462823, 552034
> TEST=manual
>
> Committed: https://crrev.com/1e24fe57a4ca921355bb1506f5a79627647a8c16
> Cr-Commit-Position: refs/heads/master@{#360319}

TBR=dzhioev@chromium.org,rogerta@chromium.org,stevenjb@chromium.org,oshima@chromium.org,alemate@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=462823, 552034
Committed: https://crrev.com/dede4c3836de2dddda5a484f098bba7152a6779b
Cr-Commit-Position: refs/heads/master@{#360369}

[hcarmona, 2015-11-18 18:36:59]

Created Revert of This CL replaces e-mail with AccountId on user selection
screen.

[commit-bot: I haz the power, 2015-11-18 18:37:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1454153002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1454153002/1

[commit-bot: I haz the power, 2015-11-18 18:40:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-18 18:41:57]

Patchset 1 (id:??) landed as
https://crrev.com/dede4c3836de2dddda5a484f098bba7152a6779b
Cr-Commit-Position: refs/heads/master@{#360369}

[hcarmona, 2015-11-18 21:48:40]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1455263002/ by hcarmona@chromium.org.

The reason for reverting is: This did not fix issues, reverting the revert..