Support new --arc-availability flag.

chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc

Index: chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
diff --git a/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc b/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
index f785b605d07f453dc9b4b73d0513504ee3614911..17f854c48a9e5aaf30bd671e18122234bce0ea04 100644
--- a/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
+++ b/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
@@ -880,7 +880,11 @@ void ChromeUserManagerImpl::ArcKioskAppLoggedIn(user_manager::User* user) {
       user_manager::User::USER_IMAGE_INVALID, false);
 
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  command_line->AppendSwitch(chromeos::switches::kEnableArc);
+  // This works partially, because sevices calling IsArcAvailable()
+  // before Kiosk log-in does not work.

[Yusuke Sato, 2017/02/03 19:19:02]

Any user-visible issues here? Please document if any (and please also file a
bug.)

[Sergey Poromov, 2017/02/03 22:58:57]

Generally, this line should be removed from here. However, there will be some
work around ARC++ Kiosk and kArcAvailability after this CL (~next week), so I'll
made the cleanup there.

[hidehiko, 2017/02/07 04:50:50]

Done.

+  // TODO(hidehiko|poromov|lhchavez): Find a correct approach.
+  command_line->AppendSwitchASCII(chromeos::switches::kArcAvailability,
+                                  "official-support");
   command_line->AppendSwitch(::switches::kForceAndroidAppMode);
   command_line->AppendSwitch(::switches::kSilentLaunch);