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

content/browser/download/mock_download_manager_delegate.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 CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_MANAGER_DELEGATE_H_
 #define CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_MANAGER_DELEGATE_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "content/browser/download/download_manager_delegate.h"
 
 class MockDownloadManagerDelegate : public DownloadManagerDelegate {
  public:
   virtual ~MockDownloadManagerDelegate();
   virtual void Shutdown() OVERRIDE;
   virtual bool ShouldStartDownload(int32 download_id) OVERRIDE;
   virtual void ChooseDownloadPath(TabContents* tab_contents,
                                   const FilePath& suggested_path,
                                   void* data) OVERRIDE;
   virtual bool OverrideIntermediatePath(DownloadItem* item,
                                         FilePath* intermediate_path) OVERRIDE;
   virtual TabContents* GetAlternativeTabContentsToNotifyForDownload() OVERRIDE;
+  virtual void MarkDownloadOpened(int64 db_handle) OVERRIDE;
   virtual bool ShouldOpenFileBasedOnExtension(const FilePath& path) OVERRIDE;
   virtual bool ShouldOpenDownload(DownloadItem* item) OVERRIDE;
   virtual bool ShouldCompleteDownload(DownloadItem* item) OVERRIDE;
   virtual bool GenerateFileHash() OVERRIDE;
   virtual void OnResponseCompleted(DownloadItem* item,
                                    const std::string& hash) OVERRIDE;
   virtual void AddItemToPersistentStore(DownloadItem* item) OVERRIDE;
   virtual void UpdateItemInPersistentStore(DownloadItem* item) OVERRIDE;
   virtual void UpdatePathForItemInPersistentStore(
       DownloadItem* item,
       const FilePath& new_path) OVERRIDE;
   virtual void RemoveItemFromPersistentStore(DownloadItem* item) OVERRIDE;
   virtual void RemoveItemsFromPersistentStoreBetween(
       const base::Time remove_begin,
       const base::Time remove_end) OVERRIDE;
   virtual void GetSaveDir(TabContents* tab_contents,
                           FilePath* website_save_dir,
                           FilePath* download_save_dir) OVERRIDE;
   virtual void ChooseSavePath(const base::WeakPtr<SavePackage>& save_package,
                               const FilePath& suggested_path,
                               bool can_save_as_complete) OVERRIDE;
   virtual void DownloadProgressUpdated() OVERRIDE;
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_MANAGER_DELEGATE_H_