Revert of Introduce SessionManager that will contain code to start user session on Chrome OS

Revert of Introduce SessionManager that will contain code to start user session on Chrome OS (https://codereview.chromium.org/318853004/)

Reason for revert:
Appears to have broken the kiosk and auth browser tests in http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29/builds/30916

Original issue's description:
> Introduce SessionManager that will contain code to start user session on Chrome OS
> 
> Move profile creation / session initialization (prefs/RLZ) as well as some of OAuth session init
> related code from LoginUtils to SessionManager. LoginUtils will temporarily implement
> SessionManager::Delegate interface till existing test coverage is migrated from LoginUtils interface.
> SessionManager will later use concept of UserSession (see design proposal at http://goto/cros-login-c14n).
> 
> LoginUtils::OnPrepareProfile() is split into
> StartSession()
> --PreStartSession() - things like switching logging dest
> --CreateUserSession() - will eventually create UserSession instance
> --StartCrosSession() - notify cros::SessionManager
> --NotifyUserLoggedIn() - UserManager::UserLoggedIn()
> --PrepareProfile()
> 
> PrepareProfile() - calls PM::CreateProfileAsync()
> --OnProfileCreated()
> ----InitProfilePreferences() - early initialization
> ----UserProfileInitialized()
> ------transfer signin profile auth date (cookies/proxy auth/certs)
> ------RestoreAuthSessionImpl() - OAuth2LoginManager::RestoreSession()
> ----FinalizePrepareProfile(()
> ------Own TPM (if it didn't happen for some reason)
> ------Notify SAML offline signin limiter
> ------Notify ProfileImpl
> ------chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED
> ------InitRLZ (for primary user)
>   
> 
> Minor cleanup
> * Unify DemoApp profile initialization flow with regular one
> * Don't pass display_email to LoginUtils::PrepareProfile
> * Move powerwash related prefs registration to ResetScreenHandler
> * Cleanup M31 migration code for |prefs::kProfileIsManaged| in LoginUtilsImpl::InitProfilePreferences()
> 
> BUG=370175, 276163
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276626

TBR=antrim@chromium.org,bauerb@chromium.org,nkostylev@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=370175, 276163
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276760

[please use gerrit instead, 2014-06-12 18:02:59]

Created Revert of Introduce SessionManager that will contain code to start user
session on Chrome OS

[commit-bot: I haz the power, 2014-06-12 18:10:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/rouslan@chromium.org/328383003/1

[commit-bot: I haz the power, 2014-06-12 18:40:18]

Change committed as 276760