Fixed suggesting adding more users into multi-profile session when we don't have more

ash/session/session_state_delegate.cc

Index: ash/session/session_state_delegate.cc
diff --git a/ash/session/session_state_delegate.cc b/ash/session/session_state_delegate.cc
index e55a5adf55e794ed87f55150b4704d43b1e40887..787b54f586b2cbebed42a0d79550f962f7daf728 100644
--- a/ash/session/session_state_delegate.cc
+++ b/ash/session/session_state_delegate.cc
@@ -11,4 +11,19 @@ bool SessionStateDelegate::IsInSecondaryLoginScreen() const {
       ash::SessionStateDelegate::SESSION_STATE_LOGIN_SECONDARY;
 }
 
+bool SessionStateDelegate::CanAddUserToMultiProfile(
+    SessionStateDelegate::MultiProfileAddUserError* error) const {
+  if (!IsMultiProfileAllowedByPrimaryUserPolicy()) {
+    if (error)
+      *error = MULTIPROFILE_ADD_USER_ERROR_NOT_ALLOWED_PRIMARY_USER;
+    return false;
+  }
+  if (NumberOfLoggedInUsers() >= GetMaximumNumberOfLoggedInUsers()) {
+    if (error)
+      *error = MULTIPROFILE_ADD_USER_ERROR_MAXIMUM_OF_USERS_REACHED;
+    return false;
+  }
+  return true;
+}
+
 } // namespace ash