Clean up Android DownloadManager code as most download now go through Chrome Network stack

chrome/browser/android/download/download_controller_base.h

 // Copyright 2016 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_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_BASE_H_
 #define CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_BASE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 41 matching lines @@
 // downloads.
 class DownloadControllerBase : public content::DownloadItem::Observer {
  public:
   // Returns the singleton instance of the DownloadControllerBase.
   static DownloadControllerBase* Get();
 
   // Called to set the DownloadControllerBase instance.
   static void SetDownloadControllerBase(
       DownloadControllerBase* download_controller);
 
-  // Starts a new download request with Android. Should be called on the
-  // UI thread.
-  virtual void CreateGETDownload(
-      const content::ResourceRequestInfo::WebContentsGetter& wc_getter,
-      bool must_download,
-      const DownloadInfo& info) = 0;
-
   // Should be called when a download is started. It can be either a GET
   // request with authentication or a POST request. Notifies the embedding
   // app about the download. Should be called on the UI thread.
   virtual void OnDownloadStarted(content::DownloadItem* download_item) = 0;
 
   // Called when a download is initiated by context menu.
   virtual void StartContextMenuDownload(
       const content::ContextMenuParams& params,
       content::WebContents* web_contents,
       bool is_link, const std::string& extra_headers) = 0;
@@ skipping 19 matching lines @@
   // Called to set the default download file name if it cannot be resolved
   // from url and content disposition
   virtual void SetDefaultDownloadFileName(const std::string& file_name) {}
 
  protected:
   ~DownloadControllerBase() override {}
   static DownloadControllerBase* download_controller_;
 };
 
 #endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_BASE_H_