Consistently use notifications from component updater w/ on-demand PNaCl.

chrome/browser/nacl_host/nacl_browser_delegate_impl.cc

 // Copyright 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/nacl_host/nacl_browser_delegate_impl.h"
 
 #include "base/path_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
 #include "chrome/browser/nacl_host/nacl_infobar_delegate.h"
@@ skipping 43 matching lines @@
   return chrome::VersionInfo().CreateVersionString();
 }
 
 ppapi::host::HostFactory* NaClBrowserDelegateImpl::CreatePpapiHostFactory(
     content::BrowserPpapiHost* ppapi_host) {
   return new chrome::ChromeBrowserPepperHostFactory(ppapi_host);
 }
 
 void NaClBrowserDelegateImpl::TryInstallPnacl(
     const base::Callback<void(bool)>& installed) {
-  ComponentUpdateService* cus = g_browser_process->component_updater();
   PnaclComponentInstaller* pci =
       g_browser_process->pnacl_component_installer();
-  RequestFirstInstall(cus, pci, installed);
+  if (pci)
+    pci->RequestFirstInstall(installed);
+  else
+    installed.Run(false);
 }