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

chrome/browser/extensions/webstore_installer.cc

Index: chrome/browser/extensions/webstore_installer.cc
diff --git a/chrome/browser/extensions/webstore_installer.cc b/chrome/browser/extensions/webstore_installer.cc
index a2e304bf33e2c5428f7876ca3d1c252c482fe8ea..bc21d3391e39d4e492843088bd808bd5860fbbbb 100644
--- a/chrome/browser/extensions/webstore_installer.cc
+++ b/chrome/browser/extensions/webstore_installer.cc
@@ -285,10 +285,6 @@ void WebstoreInstaller::OnDownloadUpdated(DownloadItem* download) {
     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))
@@ -300,8 +296,10 @@ void WebstoreInstaller::OnDownloadUpdated(DownloadItem* download) {
   }
 }
 
-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) {