Introduce lock screen app manager

chrome/browser/chromeos/lock_screen_apps/app_manager_impl.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_IMPL_H_
+#define CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_APP_MANAGER_IMPL_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "base/scoped_observer.h"
+#include "chrome/browser/chromeos/lock_screen_apps/app_manager.h"
+#include "components/prefs/pref_change_registrar.h"
+#include "extensions/browser/extension_registry_observer.h"
+
+class Profile;
+
+namespace extensions {
+class Extension;
+class ExtensionRegistry;
+}
+namespace lock_screen_apps {
+
+// The default implementation of lock_screen_apps::AppManager.
+class AppManagerImpl : public AppManager,
+                       public extensions::ExtensionRegistryObserver {
+ public:
+  AppManagerImpl();
+  ~AppManagerImpl() override;
+
+  // AppManager implementation:
+  void Initialize(Profile* primary_profile,
+                  Profile* lock_screen_profile) override;
+  void Start(AppManager::Observer* observer) override;
+  void Stop() override;
+  bool LaunchNoteTaking() override;
+  bool IsNoteTakingAppAvailable() const override;
+  std::string GetNoteTakingAppId() const override;
+
+  // extensions::ExtensionRegistryObserver implementation:
+  void OnExtensionLoaded(content::BrowserContext* browser_context,
+                         const extensions::Extension* extension) override;
+  void OnExtensionUnloaded(content::BrowserContext* browser_context,
+                           const extensions::Extension* extension,
+                           extensions::UnloadedExtensionReason reason) override;
+
+ private:
+  enum class State {
+    // The manager has not yet been initialized.
+    kNotInitialized,
+    // The manager is initialized, but not started. The note taking app is
+    // considered unset at this point, and cannot be launched.
+    kIdle,

[jdufault, 2017/05/26 19:15:53]

kInitializing?

Idle implies that this class actively does work over a (long) period of time.

[tbarzic, 2017/05/26 19:34:14]

Changed name to kInactive

+    // The manager is started. Lock screen note taking app, if set, is loaded
+    // and ready to be launched.
+    kStarted,
+  };
+
+  // Called when note taking related prefs change.
+  void OnNoteTakingExtensionChanged();
+
+  // Gets the currently enabled lock screen note taking app, is one is selected.
+  // If no such app exists, returns an empty string.
+  std::string FindLockScreenNoteTakingApp() const;
+
+  // Loads and enables the lock screen note taking app to the lock screen
+  // profile.
+  bool AddAppToLockScreenProfile(const std::string& app_id);
+
+  // Unloads lock screen note taking app from the lock screen profile.
+  void UnloadLockApp(const std::string& app_id);
+
+  Profile* primary_profile_ = nullptr;
+  Profile* lock_screen_profile_ = nullptr;
+
+  State state_ = State::kNotInitialized;
+  std::string lock_screen_app_id_;
+
+  PrefChangeRegistrar pref_change_registrar_;
+  ScopedObserver<extensions::ExtensionRegistry,
+                 extensions::ExtensionRegistryObserver>
+      extensions_observer_;
+
+  AppManager::Observer* observer_ = nullptr;
+
+  DISALLOW_COPY_AND_ASSIGN(AppManagerImpl);
+};
+
+}  // namespace lock_screen_apps
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_APP_MANAGER_IMPL_H_