Add support for cancellation of demuxer reads.

chrome/utility/media_galleries/ipc_data_source.h

 // Copyright 2014 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_UTILITY_MEDIA_GALLERIES_IPC_DATA_SOURCE_H_
 #define CHROME_UTILITY_MEDIA_GALLERIES_IPC_DATA_SOURCE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 17 matching lines @@
 class IPCDataSource: public media::DataSource,
                      public UtilityMessageHandler {
  public:
   // May only be called on the utility thread.
   explicit IPCDataSource(int64_t total_size);
   ~IPCDataSource() override;
 
   // Implementation of DataSource. These methods may be called on any single
   // thread. First usage of these methods attaches a thread checker.
   void Stop() override;
+  void Abort() override;
   void Read(int64_t position,
             int size,
             uint8_t* data,
             const ReadCB& read_cb) override;
   bool GetSize(int64_t* size_out) override;
   bool IsStreaming() override;
   void SetBitrate(int bitrate) override;
 
   // Implementation of UtilityMessageHandler. May only be called on the utility
   // thread.
@@ skipping 23 matching lines @@
 
   base::ThreadChecker utility_thread_checker_;
 
   // Enforces that the DataSource methods are called on one other thread only.
   base::ThreadChecker data_source_thread_checker_;
 };
 
 }  // namespace metadata
 
 #endif  // CHROME_UTILITY_MEDIA_GALLERIES_IPC_DATA_SOURCE_H_