Reauthenticate the user before launching Smart Lock setup app.

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

+// 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.
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.h"
+#include "chrome/browser/chromeos/login/lock/screen_locker.h"
+#include "chrome/browser/signin/screenlock_bridge.h"
+#include "chrome/grit/generated_resources.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/session_manager_client.h"
+#include "chromeos/login/auth/auth_status_consumer.h"
+#include "chromeos/login/auth/user_context.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/notification_service.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace chromeos {
+
+namespace {
+
+void EndReauthAttempt();
+
+// Performs the actual reauth flow and returns the user context it obtains.
+class ReauthHandler : public content::NotificationObserver,
+                      public chromeos::AuthStatusConsumer {
+ public:
+  explicit ReauthHandler(EasyUnlockReauth::UserContextCallback callback)
+      : callback_(callback) {}
+
+  virtual ~ReauthHandler() {}
+
+  bool Start() {
+    ScreenLocker* screen_locker = ScreenLocker::default_screen_locker();
+    if (screen_locker && screen_locker->locked()) {
+      DCHECK(false) << "Screen should not be locked when attempting reauth.";
+      return false;
+    }
+
+    // Only primary profile's can set up Easy Unlock right now.

[tbarzic, 2014/11/01 23:21:45]

nit: I'd remove the comment; this is explained in LOG(WARNING) message

[Tim Song, 2014/11/03 19:10:43]

Done.

+    user_manager::UserManager* user_manager = user_manager::UserManager::Get();
+    if (user_manager->GetPrimaryUser() != user_manager->GetActiveUser() ||
+        user_manager->GetUnlockUsers().size() != 1) {
+      LOG(WARNING) << "Only primary users in non-multiprofile sessions are "
+                   << "currently supported for reauth.";
+      return false;
+    }
+
+    notification_registrar_.Add(this,
+                                chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED,
+                                content::NotificationService::AllSources());
+
+    SessionManagerClient* session_manager =
+        chromeos::DBusThreadManager::Get()->GetSessionManagerClient();
+    session_manager->RequestLockScreen();
+    return true;
+  }
+
+  // content::NotificationObserver
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) {
+    CHECK(type == chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED);
+    bool is_screen_locked = *content::Details<bool>(details).ptr();
+    DCHECK(is_screen_locked);
+    notification_registrar_.RemoveAll();
+
+    // TODO(tengs): Add an explicit reauth state to the locker and account
+    // picker, so we can customize the UI.
+    ScreenLocker* screen_locker = ScreenLocker::default_screen_locker();
+    screen_locker->SetLoginStatusConsumer(this);
+
+    // Show tooltip explaining reauth.
+    ScreenlockBridge::UserPodCustomIconOptions icon_options;
+    icon_options.SetIcon(ScreenlockBridge::USER_POD_CUSTOM_ICON_NONE);
+    icon_options.SetTooltip(
+        l10n_util::GetStringUTF16(
+            IDS_SMART_LOCK_SCREENLOCK_TOOLTIP_HARDLOCK_REAUTH_USER),
+        true);
+
+    const user_manager::UserList& lock_users = screen_locker->users();
+    DCHECK(lock_users.size() == 1);
+    ScreenlockBridge::Get()->lock_handler()->ShowUserPodCustomIcon(
+        lock_users[0]->email(), icon_options);
+  }
+
+  // chromeos::AuthStatusConsumer:
+  virtual void OnAuthSuccess(
+      const chromeos::UserContext& user_context) override {
+    callback_.Run(user_context);
+    // Schedule deletion.
+    base::MessageLoopForUI::current()->PostTask(FROM_HERE,
+                                                base::Bind(&EndReauthAttempt));
+  }
+
+  virtual void OnAuthFailure(const chromeos::AuthFailure& error) override {}
+
+ private:
+  content::NotificationRegistrar notification_registrar_;
+  EasyUnlockReauth::UserContextCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReauthHandler);
+};
+
+ReauthHandler* g_reauth_handler = NULL;
+
+void EndReauthAttempt() {
+  DCHECK(base::MessageLoopForUI::IsCurrent());
+  DCHECK(g_reauth_handler);
+  if (g_reauth_handler)

[tbarzic, 2014/11/01 23:21:45]

since you have DCHECK just before this, I'd remove if (g_auth_handler)

[Tim Song, 2014/11/03 19:10:43]

Done.

+    delete g_reauth_handler;
+  g_reauth_handler = NULL;
+}
+
+}  // namespace
+
+// static.
+bool EasyUnlockReauth::ReauthForUserContext(
+    base::Callback<void(const UserContext&)> callback) {
+  DCHECK(base::MessageLoopForUI::IsCurrent());
+  if (g_reauth_handler)
+    return false;
+
+  g_reauth_handler = new ReauthHandler(callback);
+  return g_reauth_handler->Start();
+}
+
+}  // namespace chromeos