Revert of cros: Change how multi-profile is enabled. (https://codereview.chromium.org/142403002/)

Reason for revert:
Reverting due to test failures on  Linux ChromiumOS Tests (dbg)(2):

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%282%29/builds/10208

Sample:

[ RUN      ] ExistingUserControllerTestInstantiation/ExistingUserControllerTest.ExistingUserLogin/1
Xlib:  extension "RANDR" missing on display ":9".
[10911:10911:0121/193909:13908682450:WARNING:profile_io_data.cc(362)] no username_hash
[10911:10966:0121/193910:13908849000:ERROR:external_metrics.cc(98)] Couldn't write to /home/chronos/.progressive_scan_variation
[10911:10911:0121/193910:13908876865:ERROR:network_profile_handler.cc(80)] Manager properties returned from Shill don't contain the field Profiles
[10911:10911:0121/193910:13908877120:ERROR:network_sms_handler.cc(416)] NetworkSmsHandler: No list value for: Devices
[10977:10977:0122/033910:WARNING:sandbox_linux.cc(40)] Activated seccomp-bpf sandbox for process type: gpu-process.
[10911:10911:0121/193910:13909545391:FATAL:profile_helper.cc(98)] Check failed: false. 
 [0x7f1cec0da504] base::debug::StackTrace::StackTrace()
 [0x7f1cec148523] logging::LogMessage::~LogMessage()
 [0x0000041d6d42] chromeos::ProfileHelper::GetUserIdHashFromProfile()
 [0x0000040cd999] chromeos::UserManagerImpl::GetUserByProfile()
 [0x0000040cf19a] chromeos::UserManagerImpl::Observe()
 [0x7f1ce27321ac] content::NotificationServiceImpl::Notify()
 [0x0000028833c9] TestingProfile::FinishInit()
 [0x0000028823cd] TestingProfile::TestingProfile()
 [0x000000d4410e] chromeos::ExistingUserControllerTest::SetUpOnMainThread()
 [0x00000287e70b] InProcessBrowserTest::RunTestOnMainThreadLoop()
 [0x00000467b449] content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
 [0x00000467beb8] base::internal::RunnableAdapter<>::Run()
 [0x00000467be03] base::internal::InvokeHelper<>::MakeItSo()
 [0x00000467bd29] base::internal::Invoker<>::Run()
 [0x000000c216ed] base::Callback<>::Run()
 [0x00000492245d] ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
 [0x000004920842] ChromeBrowserMainParts::PreMainMessageLoopRun()
 [0x000003f2ba5d] chromeos::ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun()
 [0x7f1ce2351a38] content::BrowserMainLoop::PreMainMessageLoopRun()
 [0x7f1ce23590c2] base::internal::RunnableAdapter<>::Run()
 [0x7f1ce2358cb8] base::internal::InvokeHelper<>::MakeItSo()
 [0x7f1ce2358685] base::internal::Invoker<>::Run()
 [0x7f1ce2714465] base::Callback<>::Run()
 [0x7f1ce29a81a2] content::StartupTaskRunner::RunAllTasksNow()
 [0x7f1ce23511f0] content::BrowserMainLoop::CreateStartupTasks()
 [0x7f1ce2359b88] content::BrowserMainRunnerImpl::Initialize()
 [0x7f1ce234d983] content::BrowserMain()
 [0x00000467b3b0] content::BrowserTestBase::SetUp()
 [0x00000287d8ac] InProcessBrowserTest::SetUp()
 [0x0000029ac3a0] testing::internal::HandleSehExceptionsInMethodIfSupported<>()
 [0x0000029a857d] testing::internal::HandleExceptionsInMethodIfSupported<>()
 [0x00000299d03f] testing::Test::Run()
 [0x00000299d6ba] testing::TestInfo::Run()
 [0x00000299dc15] testing::TestCase::Run()
 [0x0000029a2687] testing::internal::UnitTestImpl::RunAllTests()
 [0x0000029ad54b] testing::internal::HandleSehExceptionsInMethodIfSupported<>()
 [0x0000029a9303] testing::internal::HandleExceptionsInMethodIfSupported<>()
 [0x0000029a1675] testing::UnitTest::Run()
 [0x0000028a186f] RUN_ALL_TESTS()
 [0x0000028a1388] base::TestSuite::Run()
 [0x00000287b1e7] (anonymous namespace)::ChromeTestLauncherDelegate::RunTestSuite()
 [0x0000046cebcf] content::LaunchTests()
 [0x00000287b550] LaunchChromeTests()
 [0x00000168a936] main
 [0x7f1cd9d2576d] __libc_start_main
 [0x000000b7c129] <unknown>


Original issue's description:
> cros: Change how multi-profile is enabled.
> 
> - Remove finch control so that enterprise enrollment is no longer required;
> - Change the default behavior for primary user to be "not-allowed" so that
>   only user with a proper enterprise policy could start a multi-profile
>   session;
> - Remove cached default behavior so that the changing default actually
>   has effect;
> 
> BUG=336268
> TEST=Manual. Only user with proper policy can start a multiprofile session.
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=246152

TBR=skuhne@chromium.org,joaodasilva@chromium.org,nkostylev@chromium.org,rtenneti@chromium.org,mukai@chromium.org,xiyuan@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=336268

Review URL: https://codereview.chromium.org/143993008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246307 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246307