ChromeOS login webui refactoring: split user selection/gaia login screens.

chrome/browser/chromeos/login/screens/gaia_screen.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/login/screens/gaia_screen.h"
+
+#include "base/logging.h"
+#include "chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h"
+
+namespace chromeos {
+
+GaiaScreen::GaiaScreen() : handler_(NULL) {
+}
+
+GaiaScreen::~GaiaScreen() {
+}
+
+void GaiaScreen::SetHandler(LoginDisplayWebUIHandler* handler) {
+  handler_ = handler;
+}
+
+}  // namespace chromeos