Reauthenticate the user before launching Smart Lock setup app.

chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h

Index: chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h
diff --git a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h
new file mode 100644
index 0000000000000000000000000000000000000000..041dc8722776e087ed1b46941b6b61cfb6efd7c5
--- /dev/null
+++ b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h
@@ -0,0 +1,31 @@
+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace chromeos {
+
+class UserContext;
+
+// Responsible for locking the screen and reauthenticating the user so we can
+// create new cryptohome keys for passwordless sign-in.
+class EasyUnlockReauth {
+ public:
+  typedef base::Callback<void(const UserContext&)> UserContextCallback;
+
+  // Launches the reauth screen to get the user context. If the screen fails
+  // for some reason, then this function will return false.
+  static bool ReauthForUserContext(UserContextCallback callback);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(EasyUnlockReauth);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_