Remove PNaCl's RequestFirstInstall, use resource throttle instead

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_updater_observer.h"
-
-#include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
-#include "content/public/browser/browser_thread.h"
-
-using content::BrowserThread;
-
-PnaclUpdaterObserver::PnaclUpdaterObserver(PnaclComponentInstaller* pci)
-    : must_observe_(false), pnacl_installer_(pci) {}
-
-PnaclUpdaterObserver::~PnaclUpdaterObserver() {}
-
-void PnaclUpdaterObserver::EnsureObserving() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  must_observe_ = true;
-}
-
-void PnaclUpdaterObserver::StopObserving() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  must_observe_ = false;
-}
-
-void PnaclUpdaterObserver::OnEvent(Events event, int extra) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (must_observe_) {
-    switch (event) {
-      default:
-        break;
-      case COMPONENT_UPDATE_READY:
-        // If the component updater says there is an UPDATE_READY w/ source
-        // being the PNaCl ID, then installation is handed off to the PNaCl
-        // installer and we can stop observing. The installer will be the one
-        // to run the callback w/ success or failure.
-        must_observe_ = false;
-        break;
-      case COMPONENT_UPDATER_SLEEPING:
-        // If the component updater sleeps before an UPDATE_READY for this
-        // component, then requests for installs were likely skipped,
-        // an error occurred, or there was no new update.
-        must_observe_ = false;
-        pnacl_installer_->NotifyInstallError();
-        break;
-    }
-  }
-}