Downloads: replace BrowserThread::FILE with task scheduler.

content/browser/download/download_file.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.
 
 #ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 
 class GURL;
 
 namespace content {
 
 class ByteStreamReader;
 
-// These objects live exclusively on the file thread and handle the writing
-// operations for one download. These objects live only for the duration that
-// the download is 'in progress': once the download has been completed or
+// These objects live exclusively on the download sequence and handle the
+// writing operations for one download. These objects live only for the duration
+// that the download is 'in progress': once the download has been completed or
 // cancelled, the DownloadFile is destroyed.
 class CONTENT_EXPORT DownloadFile {
  public:
   // Callback used with Initialize.  On a successful initialize, |reason| will
   // be DOWNLOAD_INTERRUPT_REASON_NONE; on a failed initialize, it will be
   // set to the reason for the failure.
   typedef base::Callback<void(DownloadInterruptReason reason)>
       InitializeCallback;
 
   // Callback used with Rename*().  On a successful rename |reason| will be
   // DOWNLOAD_INTERRUPT_REASON_NONE and |path| the path the rename
   // was done to.  On a failed rename, |reason| will contain the
   // error.
   typedef base::Callback<void(DownloadInterruptReason reason,
                               const base::FilePath& path)>
       RenameCompletionCallback;
 
   // Used to drop the request, when the byte stream reader should be closed on
-  // FILE thread.
+  // download sequence.
   typedef base::Callback<void(int64_t offset)> CancelRequestCallback;
 
   virtual ~DownloadFile() {}
 
   // Upon completion, |initialize_callback| will be called on the UI
   // thread as per the comment above, passing DOWNLOAD_INTERRUPT_REASON_NONE
   // on success, or a network download interrupt reason on failure.
   virtual void Initialize(const InitializeCallback& initialize_callback,
                           const CancelRequestCallback& cancel_request_callback,
                           const DownloadItem::ReceivedSlices& received_slices,
@@ skipping 35 matching lines @@
   virtual void SetPotentialFileLength(int64_t length) = 0;
 
   virtual const base::FilePath& FullPath() const = 0;
   virtual bool InProgress() const = 0;
   virtual void WasPaused() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_