Add support for cancellation of demuxer reads.

media/filters/file_data_source.cc

 // 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.
 
 #include "media/filters/file_data_source.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 11 matching lines @@
       force_streaming_(false),
       bytes_read_(0) {
   file_.Initialize(std::move(file));
 }
 
 bool FileDataSource::Initialize(const base::FilePath& file_path) {
   DCHECK(!file_.IsValid());
   return file_.Initialize(file_path);
 }
 
-void FileDataSource::Stop() {
-}
+void FileDataSource::Stop() {}
+
+void FileDataSource::Abort() {}
 
 void FileDataSource::Read(int64_t position,
                           int size,
                           uint8_t* data,
                           const DataSource::ReadCB& read_cb) {
   if (force_read_errors_ || !file_.IsValid()) {
     read_cb.Run(kReadError);
     return;
   }
 
@@ skipping 20 matching lines @@
 
 bool FileDataSource::IsStreaming() {
   return force_streaming_;
 }
 
 void FileDataSource::SetBitrate(int bitrate) {}
 
 FileDataSource::~FileDataSource() {}
 
 }  // namespace media