Make the UI an observer of downloads.

chrome/browser/download/download_service.cc

Index: chrome/browser/download/download_service.cc
diff --git a/chrome/browser/download/download_service.cc b/chrome/browser/download/download_service.cc
index dae3bc4e1d2177b6256dc7a8a3ee91cbf93b1a85..08cbf2d410adb50cb8b7ce29051aed39d30d48b8 100644
--- a/chrome/browser/download/download_service.cc
+++ b/chrome/browser/download/download_service.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/download/download_service_factory.h"
 #include "chrome/browser/download/download_status_updater.h"
+#include "chrome/browser/download/download_ui_controller.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/net/chrome_net_log.h"
@@ -55,6 +56,8 @@ ChromeDownloadManagerDelegate* DownloadService::GetDownloadManagerDelegate() {
             new DownloadHistory::HistoryAdapter(hs))));
   }
 
+  download_ui_.reset(new DownloadUIController(profile_, manager));
+
   // Include this download manager in the set monitored by the
   // global status updater.
   g_browser_process->download_status_updater()->AddManager(manager);