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

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

 // 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.
 
 #include "chrome/browser/ui/ash/launcher/launcher_extension_app_updater.h"
 
+#include "chrome/browser/chromeos/profiles/profile_helper.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/extension_constants.h"
 #include "extensions/browser/extension_registry.h"
 
 LauncherExtensionAppUpdater::LauncherExtensionAppUpdater(
     Delegate* delegate,
     content::BrowserContext* browser_context)
     : LauncherAppUpdater(delegate, browser_context) {
-  extensions::ExtensionRegistry::Get(browser_context)->AddObserver(this);
+  StartObservingExtensionRegistry();
+
+  arc::ArcAuthService* arc_auth_service = arc::ArcAuthService::Get();
+  // ArcAuthService may not be available for some unit tests.
+  if (arc_auth_service)
+    arc_auth_service->AddObserver(this);
 }
 
 LauncherExtensionAppUpdater::~LauncherExtensionAppUpdater() {
-  extensions::ExtensionRegistry::Get(browser_context())->RemoveObserver(this);
+  StopObservingExtensionRegistry();
+
+  arc::ArcAuthService* arc_auth_service = arc::ArcAuthService::Get();
+  if (arc_auth_service)
+    arc_auth_service->RemoveObserver(this);
 }
 
 void LauncherExtensionAppUpdater::OnExtensionLoaded(
     content::BrowserContext* browser_context,
     const extensions::Extension* extension) {
   delegate()->OnAppInstalled(browser_context, extension->id());
 }
 
 void LauncherExtensionAppUpdater::OnExtensionUnloaded(
     content::BrowserContext* browser_context,
     const extensions::Extension* extension,
     extensions::UnloadedExtensionInfo::Reason reason) {
   if (reason == extensions::UnloadedExtensionInfo::REASON_UNINSTALL)
     delegate()->OnAppUninstalled(browser_context, extension->id());
   else
     delegate()->OnAppUpdated(browser_context, extension->id());
 }
+
+void LauncherExtensionAppUpdater::OnExtensionUninstalled(
+    content::BrowserContext* browser_context,
+    const extensions::Extension* extension,
+    extensions::UninstallReason reason) {
+  if (reason == extensions::UNINSTALL_REASON_FOR_TESTING)
+    delegate()->OnAppUninstalled(browser_context, extension->id());
+}
+
+void LauncherExtensionAppUpdater::OnShutdown(
+    extensions::ExtensionRegistry* registry) {
+  DCHECK_EQ(extension_registry_, registry);
+  StopObservingExtensionRegistry();
+}
+
+void LauncherExtensionAppUpdater::OnOptInChanged(
+    arc::ArcAuthService::State state) {
+  if (!chromeos::ProfileHelper::IsPrimaryProfile(
+          Profile::FromBrowserContext(browser_context()))) {
+    return;
+  }
+  UpdateHostApps();
+}
+
+void LauncherExtensionAppUpdater::StartObservingExtensionRegistry() {
+  DCHECK(!extension_registry_);
+  extension_registry_ = extensions::ExtensionRegistry::Get(browser_context());
+  extension_registry_->AddObserver(this);
+}
+
+void LauncherExtensionAppUpdater::StopObservingExtensionRegistry() {
+  if (extension_registry_)
+    extension_registry_->RemoveObserver(this);

[Mr4D (OOO till 08-26), 2016/06/15 23:03:23]

you might do if (!extension_registry_) return; ..

+  extension_registry_ = nullptr;
+}
+
+void LauncherExtensionAppUpdater::UpdateHostApps() {
+  if (!extension_registry_)
+    return;
+
+  UpdateHostApps(extension_registry_->enabled_extensions());
+  UpdateHostApps(extension_registry_->disabled_extensions());
+  UpdateHostApps(extension_registry_->terminated_extensions());
+  UpdateHostApp(extension_misc::kChromeAppId);
+}
+
+void LauncherExtensionAppUpdater::UpdateHostApps(
+    const extensions::ExtensionSet& extensions) {
+  content::BrowserContext* context = browser_context();
+  extensions::ExtensionSet::const_iterator it;
+  for (it = extensions.begin(); it != extensions.end(); ++it) {
+    if ((*it)->is_hosted_app())
+      delegate()->OnAppUpdated(context, (*it)->id());
+  }
+}
+
+void LauncherExtensionAppUpdater::UpdateHostApp(const std::string& app_id) {
+  delegate()->OnAppUpdated(browser_context(), app_id);
+}