ARC: Add badge for Chrome hosted Apps if Arc++ is enabled.

chrome/browser/ui/ash/launcher/launcher_extension_app_updater.h

 // Copyright 2016 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_ASH_LAUNCHER_LAUNCHER_EXTENSION_APP_UPDATER_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_LAUNCHER_EXTENSION_APP_UPDATER_H_
 
 #include "base/macros.h"
+#include "chrome/browser/chromeos/arc/arc_auth_service.h"
 #include "chrome/browser/ui/ash/launcher/launcher_app_updater.h"
 #include "extensions/browser/extension_registry_observer.h"
 
+namespace extensions {
+class ExtensionSet;
+}  // namespace extensions
+
 class LauncherExtensionAppUpdater
     : public LauncherAppUpdater,
-      public extensions::ExtensionRegistryObserver {
+      public extensions::ExtensionRegistryObserver,
+      public arc::ArcAuthService::Observer {
  public:
   LauncherExtensionAppUpdater(Delegate* delegate,
                               content::BrowserContext* browser_context);
   ~LauncherExtensionAppUpdater() override;
 
   // ExtensionRegistryObserver:
   void OnExtensionLoaded(content::BrowserContext* browser_context,
                          const extensions::Extension* extension) override;
   void OnExtensionUnloaded(
       content::BrowserContext* browser_context,
       const extensions::Extension* extension,
       extensions::UnloadedExtensionInfo::Reason reason) override;
+  void OnExtensionUninstalled(content::BrowserContext* browser_context,
+                              const extensions::Extension* extension,
+                              extensions::UninstallReason reason) override;
+  void OnShutdown(extensions::ExtensionRegistry* registry) override;
+
+  // arc::ArcAuthService::Observer:
+  void OnOptInChanged(arc::ArcAuthService::State state) override;
 
  private:
+  void StartObservingExtensionRegistry();
+  void StopObservingExtensionRegistry();
+
+  void UpdateHostApps();
+  void UpdateHostApps(const extensions::ExtensionSet& extensions);
+  void UpdateHostApp(const std::string& app_id);

[xiyuan, 2016/06/17 20:57:29]

nit: to be consistent, HostApp -> HostedApp for all three.

i.e.
  UpdateHostApps -> UpdateHostedApps
  UpdateHostApp -> UpdateHostedApp

+
+  extensions::ExtensionRegistry* extension_registry_ = nullptr;
+
   DISALLOW_COPY_AND_ASSIGN(LauncherExtensionAppUpdater);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_LAUNCHER_EXTENSION_APP_UPDATER_H_