Replace deprecated base::NonThreadSafe in media/audio in favor of SequenceChecker.

media/audio/sounds/audio_stream_handler.h

 // Copyright 2013 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 MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_
 #define MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_
 
 #include <stddef.h>
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/sequence_checker.h"
 #include "base/strings/string_piece.h"
-#include "base/threading/non_thread_safe.h"
 #include "base/time/time.h"
 #include "media/audio/audio_io.h"
 #include "media/base/audio_parameters.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 // This class sends a sound to the audio manager.
-class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
+class MEDIA_EXPORT AudioStreamHandler {
  public:
   class TestObserver {
    public:
     virtual ~TestObserver() {}
 
     // Following methods will be called only from the audio thread.
 
     // Called when AudioOutputStreamProxy::Start() was successfully called.
     virtual void OnPlay() = 0;
 
@@ skipping 29 matching lines @@
 
   class AudioStreamContainer;
 
   static void SetObserverForTesting(TestObserver* observer);
   static void SetAudioSourceForTesting(
       AudioOutputStream::AudioSourceCallback* source);
 
   base::TimeDelta duration_;
   std::unique_ptr<AudioStreamContainer> stream_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(AudioStreamHandler);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_