Make the UI an observer of downloads.

content/browser/download/download_item_impl.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_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 62 matching lines @@
                    const DownloadCreateInfo& info,
                    const net::BoundNetLog& bound_net_log);
 
   // Constructing for the "Save Page As..." feature:
   // |bound_net_log| is constructed externally for our use.
   DownloadItemImpl(DownloadItemImplDelegate* delegate,
                    const base::FilePath& path,
                    const GURL& url,
                    DownloadId download_id,
                    const std::string& mime_type,
+                   scoped_ptr<DownloadRequestHandleInterface> request_handle,
                    const net::BoundNetLog& bound_net_log);
 
   virtual ~DownloadItemImpl();
 
   // DownloadItem
   virtual void AddObserver(DownloadItem::Observer* observer) OVERRIDE;
   virtual void RemoveObserver(DownloadItem::Observer* observer) OVERRIDE;
   virtual void UpdateObservers() OVERRIDE;
   virtual void DangerousDownloadValidated() OVERRIDE;
   virtual void Pause() OVERRIDE;
@@ skipping 388 matching lines @@
   const net::BoundNetLog bound_net_log_;
 
   base::WeakPtrFactory<DownloadItemImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_