Reland DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

chrome/browser/extensions/webstore_installer.cc

 // Copyright (c) 2012 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/extensions/webstore_installer.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 267 matching lines @@
 void WebstoreInstaller::OnDownloadUpdated(DownloadItem* download) {
   CHECK_EQ(download_item_, download);
 
   switch (download->GetState()) {
     case DownloadItem::CANCELLED:
       ReportFailure(kDownloadCanceledError);
       break;
     case DownloadItem::INTERRUPTED:
       ReportFailure(kDownloadInterruptedError);
       break;
-    case DownloadItem::REMOVING:
-      download_item_->RemoveObserver(this);
-      download_item_ = NULL;
-      break;
     case DownloadItem::COMPLETE:
       // Wait for other notifications if the download is really an extension.
       if (!download_crx_util::IsExtensionDownload(*download))
         ReportFailure(kInvalidDownloadError);
       break;
     default:
       // Continue listening if the download is not in one of the above states.
       break;
   }
 }
 
-void WebstoreInstaller::OnDownloadOpened(DownloadItem* download) {
+void WebstoreInstaller::OnDownloadDestructed(DownloadItem* download) {
   CHECK_EQ(download_item_, download);
+  download_item_->RemoveObserver(this);
+  download_item_ = NULL;
 }
 
 void WebstoreInstaller::StartDownload(const FilePath& file) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (file.empty() || !controller_->GetWebContents()) {
     ReportFailure(kDownloadDirectoryError);
     return;
   }
 
@@ skipping 26 matching lines @@
 }
 
 void WebstoreInstaller::ReportSuccess() {
   if (delegate_) {
     delegate_->OnExtensionInstallSuccess(id_);
     delegate_ = NULL;
   }
 
   Release();  // Balanced in Start().
 }