cryptohome: Make CryptohomeClient::Unmount non-blocking

chromeos/login/auth/cryptohome_authenticator.h

Index: chromeos/login/auth/cryptohome_authenticator.h
diff --git a/chromeos/login/auth/cryptohome_authenticator.h b/chromeos/login/auth/cryptohome_authenticator.h
index 86c7001be202f698ac73db369a11e8495f46f4ee..a1286e09cb71ccd77b1f789f3df7f3643f38fe56 100644
--- a/chromeos/login/auth/cryptohome_authenticator.h
+++ b/chromeos/login/auth/cryptohome_authenticator.h
@@ -14,6 +14,7 @@
 #include "base/synchronization/lock.h"
 #include "base/task_runner.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_method_call_status.h"
 #include "chromeos/login/auth/auth_attempt_state.h"
 #include "chromeos/login/auth/auth_attempt_state_resolver.h"
 #include "chromeos/login/auth/authenticator.h"
@@ -236,6 +237,9 @@ class CHROMEOS_EXPORT CryptohomeAuthenticator
   // Handles completion of the ownership check and continues login.
   void OnOwnershipChecked(bool is_owner);
 
+  // Handles completion of cryptohome unmount.
+  void OnUnmount(DBusMethodCallStatus call_status, bool success);
+
   // Signal login completion status for cases when a new user is added via
   // an external authentication provider (i.e. GAIA extension).
   void ResolveLoginCompletionStatus();