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..9ec0cf27d7bdb2e0390663e32523b0af9d86be4e 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 +880,10 @@ 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()

[Yusuke Sato, 2017/02/02 18:14:06]

I'm not sure if I understand the comment... Do we need a TODO here?

[hidehiko, 2017/02/03 15:37:42]

Done.

+  // before Kiosk log-in does not work.
+  command_line->AppendSwitchASCII(chromeos::switches::kArcAvailability,
+                                  "official-support");
   command_line->AppendSwitch(::switches::kForceAndroidAppMode);
   command_line->AppendSwitch(::switches::kSilentLaunch);