arc: Start ARC for Public Session users.

chrome/browser/chromeos/arc/arc_auth_service.cc

Index: chrome/browser/chromeos/arc/arc_auth_service.cc
diff --git a/chrome/browser/chromeos/arc/arc_auth_service.cc b/chrome/browser/chromeos/arc/arc_auth_service.cc
index b90cf0d1b515d45caed009ab95972165b8290ac7..2243486e6e4c80bea281294f26008c1ff76994de 100644
--- a/chrome/browser/chromeos/arc/arc_auth_service.cc
+++ b/chrome/browser/chromeos/arc/arc_auth_service.cc
@@ -63,8 +63,9 @@ ProvisioningResult ConvertArcSignInFailureReasonToProvisioningResult(
 }
 
 mojom::ChromeAccountType GetAccountType() {
-  return IsArcKioskMode() ? mojom::ChromeAccountType::ROBOT_ACCOUNT
-                          : mojom::ChromeAccountType::USER_ACCOUNT;
+  return IsArcKioskMode() || IsPublicSessionMode()
+             ? mojom::ChromeAccountType::ROBOT_ACCOUNT
+             : mojom::ChromeAccountType::USER_ACCOUNT;
 }
 
 }  // namespace
@@ -218,7 +219,7 @@ void ArcAuthService::GetAuthCodeDeprecated(
     const GetAuthCodeDeprecatedCallback& callback) {
   // For robot account we must use RequestAccountInfo because it allows
   // to specify account type.
-  DCHECK(!IsArcKioskMode());
+  DCHECK(!IsArcKioskMode() && !IsPublicSessionMode());
   RequestAccountInfoInternal(
       base::MakeUnique<ArcAuthService::AccountInfoNotifier>(callback));
 }
@@ -272,8 +273,8 @@ void ArcAuthService::RequestAccountInfoInternal(
   }
   // For non-AD enrolled devices an auth code is fetched.
   std::unique_ptr<ArcAuthCodeFetcher> auth_code_fetcher;
-  if (IsArcKioskMode()) {
-    // In Kiosk mode, use Robot auth code fetching.
+  if (IsArcKioskMode() || IsPublicSessionMode()) {
+    // In Kiosk and public session mode, use Robot auth code fetching.
     auth_code_fetcher = base::MakeUnique<ArcRobotAuthCodeFetcher>();
   } else if (base::FeatureList::IsEnabled(arc::kArcUseAuthEndpointFeature)) {
     // Optionally retrieve auth code in silent mode.
@@ -287,7 +288,8 @@ void ArcAuthService::RequestAccountInfoInternal(
     // Otherwise, show LSO page and let user click "Sign in" button.
     // Here, support_host should be available always. The case support_host is
     // not created is when 1) IsArcOptInVerificationDisabled() is true or 2)
-    // IsArcKioskMode() is true. Both cases are handled above.
+    // IsArcKioskMode() or IsPublicSessionMode() is true.
+    // Both cases are handled above.
     auth_code_fetcher = base::MakeUnique<ArcManualAuthCodeFetcher>(
         ArcSessionManager::Get()->auth_context(),
         ArcSessionManager::Get()->support_host());