Start moving signin code out of browser/sync.

chrome/browser/ui/webui/signin/login_ui_service.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_
+#define CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_
+#pragma once
+
+#include "chrome/browser/profiles/profile_keyed_service.h"
+
+class Profile;
+
+namespace content {
+class WebUI;
+};
+
+// The LoginUIService helps track per-profile information for the login UI -
+// for example, whether there is login UI currently on-screen.
+class LoginUIService : public ProfileKeyedService {
+ public:
+  explicit LoginUIService(Profile* profile);

[James Hawkins, 2012/02/10 23:08:01]

Document |profile|.

[Andrew T Wilson (Slow), 2012/02/11 01:50:45]

Done.

+  virtual ~LoginUIService();
+
+  // Gets the currently active login UI, or null if no login UI is active.
+  content::WebUI* current_login_ui() const {
+    return ui_;
+  }
+
+  // Sets the currently active login UI. It is illegal to call this if there is
+  // already login UI visible.
+  void SetLoginUI(content::WebUI* ui);
+
+  // If the passed UI is the current login UI, clears it (called when login UI
+  // is being shut down).
+  void ClearLoginUI(content::WebUI* ui);

[James Hawkins, 2012/02/10 23:08:01]

s/Clear/Reset/ may be clearer given that we're referring to UI, and clear could
be misconstrued as a visual command.

[Andrew T Wilson (Slow), 2012/02/11 01:50:45]

Done.

+
+  // Brings the current login UI for this profile to the foreground (it is an
+  // error to call this if there is no visible login UI.
+  void FocusLoginUI();
+
+  // Displays the login dialog to the user.
+  void ShowLoginUI();
+
+ private:
+  // The currently active login UI, or null if none.
+  content::WebUI* ui_;

[James Hawkins, 2012/02/10 23:08:01]

Document ownership (likely weak ptr).

[Andrew T Wilson (Slow), 2012/02/11 01:50:45]

Done.

+
+  // The profile this service is associated with.
+  Profile* profile_;
+};
+
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_