Make the UI an observer of downloads.

content/public/browser/download_manager_delegate.h

Index: content/public/browser/download_manager_delegate.h
diff --git a/content/public/browser/download_manager_delegate.h b/content/public/browser/download_manager_delegate.h
index 7c7d85c3310b01536730d919e6f83384b0fedbc8..4296839a8b40b936022ac486c1a9d2d66a470bc7 100644
--- a/content/public/browser/download_manager_delegate.h
+++ b/content/public/browser/download_manager_delegate.h
@@ -74,11 +74,6 @@ class CONTENT_EXPORT DownloadManagerDelegate {
   virtual bool DetermineDownloadTarget(DownloadItem* item,
                                        const DownloadTargetCallback& callback);
 
-  // Called when the download system wants to alert a WebContents that a
-  // download has started, but the TabConetnts has gone away. This lets an
-  // delegate return an alternative WebContents. The delegate can return NULL.
-  virtual WebContents* GetAlternativeWebContentsToNotifyForDownload();
-
   // Tests if a file type should be opened automatically.
   virtual bool ShouldOpenFileBasedOnExtension(const FilePath& path);