Add new UMA stats to get a handle on Downloads UI Usage

chrome/browser/ui/views/download/download_shelf_view.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 136 matching lines @@
   // by View.
   views::Link* show_all_view_;
 
   // Button for closing the downloads. This is contained as a child, and
   // deleted by View.
   views::ImageButton* close_button_;
 
   // The window this shelf belongs to.
   BrowserView* parent_;
 
+  // Whether we are auto-closing.
+  bool auto_closed_;
+
   views::MouseWatcher mouse_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadShelfView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_