Downloads: replace BrowserThread::FILE with task scheduler.

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 16 matching lines @@
 #ifndef CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_H_
 #define CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/files/file_path.h"
-#include "base/sequenced_task_runner_helpers.h"
+#include "base/sequenced_task_runner.h"
 #include "base/time/time.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_url_parameters.h"
 #include "net/base/net_errors.h"
 
 class GURL;
 
 namespace content {
 
 class BrowserContext;
 class ByteStreamReader;
 class DownloadManagerDelegate;
 struct DownloadCreateInfo;
 
 // Browser's download manager: manages all downloads and destination view.
 class CONTENT_EXPORT DownloadManager : public base::SupportsUserData::Data {
  public:
   ~DownloadManager() override {}
 
+  // Returns the task runner that's used for all download-related blocking
+  // tasks, such as file IO.
+  static scoped_refptr<base::SequencedTaskRunner> GetTaskRunner();
+
   // Sets/Gets the delegate for this DownloadManager. The delegate has to live
   // past its Shutdown method being called (by the DownloadManager).
   virtual void SetDelegate(DownloadManagerDelegate* delegate) = 0;
   virtual DownloadManagerDelegate* GetDelegate() const = 0;
 
   // Shutdown the download manager. Content calls this when BrowserContext is
   // being destructed. If the embedder needs this to be called earlier, it can
   // call it. In that case, the delegate's Shutdown() method will only be called
   // once.
   virtual void Shutdown() = 0;
@@ skipping 117 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_