Split NTPLoginHandler across chrome://apps and chrome://history.

chrome/browser/ui/webui/profile_info_watcher.h

+// Copyright 2015 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_PROFILE_INFO_WATCHER_H_
+#define CHROME_BROWSER_UI_WEBUI_PROFILE_INFO_WATCHER_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/prefs/pref_member.h"
+#include "chrome/browser/profiles/profile_info_cache_observer.h"
+
+class Profile;
+class SigninManagerBase;
+
+// Watches profiles for changes in their cached info (e.g. the authenticated
+// username changes).
+class ProfileInfoWatcher : public ProfileInfoCacheObserver {
+ public:
+  ProfileInfoWatcher(Profile* profile, const base::Closure& callback);
+  ~ProfileInfoWatcher() override;
+
+  // Gets the authenticated username (e.g. username@gmail.com) for |profile_|.
+  std::string GetAuthenticatedUsername() const;
+
+ private:
+  // ProfileInfoCacheObserver:
+  void OnProfileAuthInfoChanged(const base::FilePath& profile_path) override;
+
+  // Gets the SigninManagerBase for |profile_|.
+  SigninManagerBase* GetSigninManager() const;
+
+  // Runs |callback_| when a profile changes. No-ops if |GetSigninManager()|
+  // returns nullptr.
+  void RunCallback();
+
+  // Weak reference to the profile this class observes.
+  Profile* const profile_;
+
+  // Called when the authenticated username changes.
+  base::Closure callback_;
+
+  BooleanPrefMember signin_allowed_pref_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProfileInfoWatcher);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_PROFILE_INFO_WATCHER_H_