[downloads] Remove DownloadManager::RemoveAllDownloads.

content/public/browser/download_manager.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.
 //
 // The DownloadManager object manages the process of downloading, including
 // updates to the history system and providing the information for displaying
 // the downloads view in the Destinations tab. There is one DownloadManager per
 // active browser context in Chrome.
 //
 // Download observers:
@@ skipping 98 matching lines @@
 
   // Remove downloads whose URLs match the |url_filter| and are within
   // the given time constraints - after remove_begin (inclusive) and before
   // remove_end (exclusive). You may pass in null Time values to do an unbounded
   // delete in either direction.
   virtual int RemoveDownloadsByURLAndTime(
       const base::Callback<bool(const GURL&)>& url_filter,
       base::Time remove_begin,
       base::Time remove_end) = 0;
 
-  // Remove all downloads will delete all downloads. The number of downloads
-  // deleted is returned back to the caller.
-  virtual int RemoveAllDownloads() = 0;
-
   // See DownloadUrlParameters for details about controlling the download.
   virtual void DownloadUrl(
       std::unique_ptr<DownloadUrlParameters> parameters) = 0;
 
   // Allow objects to observe the download creation process.
   virtual void AddObserver(Observer* observer) = 0;
 
   // Remove a download observer from ourself.
   virtual void RemoveObserver(Observer* observer) = 0;
 
@@ skipping 48 matching lines @@
   // if you need to keep track of a specific download. (http://crbug.com/593020)
   virtual DownloadItem* GetDownload(uint32_t id) = 0;
 
   // Get the download item for |guid|.
   virtual DownloadItem* GetDownloadByGuid(const std::string& guid) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_H_