Prevent accidental addition of public sessions to regular user list

When ephemeral users are enabled, Chrome removes existing regular users
on start. This accidentally causes public session users to be copied to
the regular user list. The CL fixes that.

BUG=178100
TEST=Manual


Review URL: https://chromiumcodereview.appspot.com/12320094

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@184848 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/login/user_manager_impl.cc

@@ -895,7 +895,8 @@ void UserManagerImpl::RetrieveTrustedDevicePolicies() {
         it = users_.erase(it);
         changed = true;
       } else {
-        prefs_users_update->Append(new base::StringValue(user_email));
+        if ((*it)->GetType() != User::USER_TYPE_PUBLIC_ACCOUNT)
+          prefs_users_update->Append(new base::StringValue(user_email));
         ++it;
       }
     }