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/memory/weak_ptr.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 extensions
+
 namespace lock_screen_apps {
 
 // The default implementation of lock_screen_apps::AppManager.
-class AppManagerImpl : public 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(const base::Closure& note_taking_changed_callback) 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.
+    kInactive,
+    // The manager is started. Lock screen note taking app, if set, is loaded
+    // and ready to be launched.
+    kActive,
+    // The manager is started, but app is still being installed into the lock
+    // screen apps profile.
+    kActivating,
+    // The manager is started, and there is no available lock screen enabled
+    // app.
+    kAppUnavailable,
+  };
+
+  // Called on UI thread when the lock screen app profile is initialized with
+  // lock screen app assets. It completes the app installation to the lock
+  // screen app profile.
+  // |app| - the installing app. Cann be nullptr in case the app assets
+  //     installation failed.
+  void CompleteLockScreenAppInstall(
+      int install_id,
+      const scoped_refptr<const extensions::Extension>& app);
+
+  // Installs app to the lock screen profile's extension service and enables
+  // the app.
+  void InstallAndEnableLockScreenAppInLockScreenProfile(
+      const extensions::Extension* app);
+
+  // 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;
+
+  // Starts installing the lock screen note taking app to the lock screen
+  // profile.
+  // Returns the state to which the app manager should move as a result of this
+  // method.
+  State AddAppToLockScreenProfile(const std::string& app_id);
+
+  // Uninstalls lock screen note taking app from the lock screen profile.
+  void RemoveAppFromLockScreenProfile(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_;
+
   base::Closure note_taking_changed_callback_;
 
+  // Counts app installs. Passed to app install callback as install request
+  // identifier to determine whether the completed install is stale.
+  int install_count_ = 0;
+
+  base::WeakPtrFactory<AppManagerImpl> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AppManagerImpl);
 };
 
 }  // namespace lock_screen_apps
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_APP_MANAGER_IMPL_H_