Revert of This CL replaces user_manager::UserID with AccountId.

Revert of This CL replaces user_manager::UserID with AccountId. (patchset #12 id:210001 of https://codereview.chromium.org/1412813003/ )

Reason for revert:
breaks the GN build on windows:

FAILED: E:/b/depot_tools/python276_bin/python.exe gyp-win-tool link-wrapper environment.x86 False link.exe /nologo /OUT:ash_unittests.exe /PDB:ash_unittests.exe.pdb @ash_unittests.exe.rsp
test_session_state_delegate.obj : error LNK2019: unresolved external symbol "public: __thiscall AccountId::AccountId(class AccountId const &)" (??0AccountId@@QAE@ABV0@@Z) referenced in function "public: virtual class AccountId __thiscall ash::test::MockUserInfo::GetAccountId(void)const " (?GetAccountId@MockUserInfo@test@ash@@UBE?AVAccountId@@XZ)

test_session_state_delegate.obj : error LNK2019: unresolved external symbol "public: bool __thiscall AccountId::operator==(class AccountId const &)const " (??8AccountId@@QBE_NABV0@@Z) referenced in function "public: virtual void __thiscall ash::test::TestSessionStateDelegate::SwitchActiveUser(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?SwitchActiveUser@TestSessionStateDelegate@test@ash@@UAEXABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)

test_session_state_delegate.obj : error LNK2019: unresolved external symbol "public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const & __thiscall AccountId::GetUserEmail(void)const " (?GetUserEmail@AccountId@@QBEABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ) referenced in function "public: virtual void __thiscall ash::test::TestSessionStateDelegate::SwitchActiveUser(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?SwitchActiveUser@TestSessionStateDelegate@test@ash@@UAEXABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)

test_session_state_delegate.obj : error LNK2019: unresolved external symbol "public: static class AccountId __cdecl AccountId::FromUserEmail(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?FromUserEmail@AccountId@@SA?AV1@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "class AccountId __cdecl ash::test::`anonymous namespace'::GetAccountIdFromEmail(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?GetAccountIdFromEmail@?A0x8b8d8028@test@ash@@YA?AVAccountId@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)

ash_unittests.exe : fatal error LNK1120: 4 unresolved externals

ninja: build stopped: subcommand failed.

Original issue's description:
> This CL replaces user_manager::UserID with AccountId.
>
> This CL replaces API of user_manager::UserManager, thus modifying API of all
> child objects, and all calls to UserManager.
>
> This is part of transition to AccountId.
>
> BUG=468875
> TEST=manual
>
> Committed: https://crrev.com/cd06408625de9e0d5cf4c7c1ede412cb5c82542b
> Cr-Commit-Position: refs/heads/master@{#357119}

TBR=jochen@chromium.org,achuith@chromium.org,bshe@chromium.org,rogerta@chromium.org,sky@chromium.org,stevenjb@chromium.org,alemate@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=468875
Committed: https://crrev.com/6fa8e13e56429c6cefbba3d5a76f2c41ce28581b
Cr-Commit-Position: refs/heads/master@{#357219}

[rjkroege, 2015-10-30 23:20:48]

Created Revert of This CL replaces user_manager::UserID with AccountId.

[commit-bot: I haz the power, 2015-10-30 23:21:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1425093004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1425093004/1

[commit-bot: I haz the power, 2015-10-30 23:26:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-30 23:27:27]

Patchset 1 (id:??) landed as
https://crrev.com/6fa8e13e56429c6cefbba3d5a76f2c41ce28581b
Cr-Commit-Position: refs/heads/master@{#357219}

[achuithb, 2015-11-02 19:44:21]

On 2015/10/30 23:20:48, rjkroege wrote:
> Created Revert of This CL replaces user_manager::UserID with AccountId.

This CL passed the CQ. Is there a trybot on the CQ for this?

[rjkroege, 2015-11-02 20:15:55]

On 2015/11/02 19:44:21, achuithb wrote:
> On 2015/10/30 23:20:48, rjkroege wrote:
> > Created Revert of This CL replaces user_manager::UserID with AccountId.
> 
> This CL passed the CQ. Is there a trybot on the CQ for this?

My understanding is that there isn't. I would hope that this is a temporary
issue related to the roll-out of GN. Sorry for the inconvenience.