Make the UI an observer of downloads.

content/public/browser/download_manager_delegate.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_DELEGATE_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/file_path.h"
@@ skipping 56 matching lines @@
   //
   // The state of the |item| shouldn't be modified during the process of
   // filename determination save for external data (GetExternalData() /
   // SetExternalData()).
   //
   // If the download should be canceled, |callback| should be invoked with an
   // empty |target_path| argument.
   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);
 
   // Allows the delegate to delay completion of the download.  This function
   // will either return true (in which case the download may complete)
   // or will call the callback passed when the download is ready for
   // completion.  This routine should only be called once per download.
   virtual bool ShouldCompleteDownload(
       DownloadItem* item,
       const base::Closure& complete_callback);
@@ skipping 23 matching lines @@
                               const SavePackagePathPickedCallback& callback) {
   }
 
  protected:
   virtual ~DownloadManagerDelegate();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_DELEGATE_H_