Introduce lock screen app manager interface

chrome/browser/chromeos/lock_screen_apps/app_manager.h

+// Copyright 2017 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_LOCK_SCREEN_APPS_APP_MANAGER_H_
+#define CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_APP_MANAGER_H_
+
+#include <string>
+
+#include "base/callback_forward.h"
+
+class Profile;
+
+namespace lock_screen_apps {
+
+// Interface for managing lock screen enabled action handler apps in the lock
+// screen enabled profile. Initially, it will be used primarily to manage lock
+// screen note taking apps.
+class AppManager {
+ public:
+  virtual ~AppManager() {}
+
+  // Initializes the manager.
+  // |primary_profile| - the profile which is the source of the lock screen
+  //     action handler app (if one is set). This is the profile whose
+  //     settings are used to determine whether and for which app lock screen
+  //     action is enabled, and it should be associated with the primary user.
+  // |lock_screen_profile| - the profile in which lock screen apps should be
+  //     installed and launched. This profile should be annonymous - i.e. not
+  //     associated with any user.
+  virtual void Initialize(Profile* primary_profile,
+                          Profile* lock_screen_profile) = 0;
+
+  // Activates the manager - this should ensure that lock screen enabled note
+  // taking app, if available, is loaded and enabled in the lock screen profile.
+  // |note_taking_changed_callback| - used to notify the client when the note
+  //      taking app availability changes. It's cleared when the AppManager is
+  //      stopped. It is not expected to be run after the app manager instance
+  //      is destroyed.
+  virtual void Start(const base::Closure& note_taking_changed_callback) = 0;
+
+  // Stops the manager. After this is called, the app can be unloaded from the
+  // lock screen enabled profile. Subsequent launch requests should not be
+  // allowed.
+  virtual void Stop() = 0;
+
+  // If lock screen note taking app is available, launches the app with lock
+  // screen note taking action.
+  // Returns whether the app launch was attempted.
+  virtual bool LaunchNoteTaking() = 0;
+
+  // Returns whether a lock screen note taking is enabled and ready to launch.
+  virtual bool IsNoteTakingAppAvailable() const = 0;
+
+  // Returns the lock screen enabled lock screen note taking app, if a note
+  // taking app is enabled on lock screen (for primary profile).
+  virtual std::string GetNoteTakingAppId() const = 0;
+};
+
+}  // namespace lock_screen_apps
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_APP_MANAGER_H_