Replace early check for PNaCl with an on-demand check.

chrome/browser/component_updater/pnacl/pnacl_updater_observer.cc

 // Copyright (c) 2013 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/component_updater/pnacl/pnacl_profile_observer.h"
+#include "chrome/browser/component_updater/pnacl/pnacl_updater_observer.h"
 
 #include "base/logging.h"
 #include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/notification_service.h"
 
-PnaclProfileObserver::PnaclProfileObserver(
+PnaclUpdaterObserver::PnaclUpdaterObserver(
     PnaclComponentInstaller* installer) : pnacl_installer_(installer) {
-  // We only need to observe NOTIFICATION_LOGIN_USER_CHANGED for ChromeOS
-  // (and it's only defined for ChromeOS).
-#if defined(OS_CHROMEOS)
   registrar_.Add(this,
-                 chrome::NOTIFICATION_LOGIN_USER_CHANGED,
+                 chrome::NOTIFICATION_COMPONENT_UPDATER_SLEEPING,
                  content::NotificationService::AllSources());
-#endif
 }
 
-PnaclProfileObserver::~PnaclProfileObserver() { }
+PnaclUpdaterObserver::~PnaclUpdaterObserver() { }
 
-void PnaclProfileObserver::Observe(
+void PnaclUpdaterObserver::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-#if defined(OS_CHROMEOS)
-  if (type == chrome::NOTIFICATION_LOGIN_USER_CHANGED) {
-    pnacl_installer_->ReRegisterPnacl();
+  if (type == chrome::NOTIFICATION_COMPONENT_UPDATER_SLEEPING) {
+    // If the component updater sleeps before a NotifyInstallSuccess,
+    // then requests for installs were likely skipped, or an error occurred.
+    pnacl_installer_->NotifyInstallError();
     return;
   }
-  NOTREACHED() << "Unexpected notification observed";
-#endif
 }