arc: Start ARC for Public Session users.

chrome/browser/chromeos/arc/arc_session_manager.cc

Index: chrome/browser/chromeos/arc/arc_session_manager.cc
diff --git a/chrome/browser/chromeos/arc/arc_session_manager.cc b/chrome/browser/chromeos/arc/arc_session_manager.cc
index 288b8fb2938be36489af86827ab3c294dd9dbb78..9300cfbc2ba517d24f8ac9aec569c67ec252ac93 100644
--- a/chrome/browser/chromeos/arc/arc_session_manager.cc
+++ b/chrome/browser/chromeos/arc/arc_session_manager.cc
@@ -573,10 +573,12 @@ void ArcSessionManager::RequestEnableImpl() {
   // set up to always start, then directly start ARC.
   // For Kiosk mode, skip ToS because it is very likely that near the device
   // there will be no one who is eligible to accept them.
-  // If opt-in verification is disabled, skip negotiation, too. This is for
-  // testing purpose.
+  // In Public Session mode ARC should be started silently without user
+  // interaction. If opt-in verification is disabled, skip negotiation, too.
+  // This is for testing purpose.
   const bool start_arc_directly = prefs->GetBoolean(prefs::kArcSignedIn) ||
                                   ShouldArcAlwaysStart() || IsArcKioskMode() ||
+                                  IsPublicSessionMode() ||
                                   IsArcOptInVerificationDisabled();
 
   // When ARC is blocked because of filesystem compatibility, do not proceed