Cast: Basic cast_receiver API for chrome.

chrome/renderer/media/cast_receiver_audio_valve.h

Index: chrome/renderer/media/cast_receiver_audio_valve.h
diff --git a/chrome/renderer/media/cast_receiver_audio_valve.h b/chrome/renderer/media/cast_receiver_audio_valve.h
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+++ b/chrome/renderer/media/cast_receiver_audio_valve.h
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+// Copyright 2015 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_RENDERER_MEDIA_CAST_RECEIVER_AUDIO_VALVE_H_
+#define CHROME_RENDERER_MEDIA_CAST_RECEIVER_AUDIO_VALVE_H_
+
+#include "base/synchronization/lock.h"
+#include "media/base/audio_capturer_source.h"
+
+namespace media {
+class AudioBus;
+}
+
+// Forwards calls to |cb| until Stop is called.
+// Thread-safe.
+// All functions may block depending on contention.
+class CastReceiverAudioValve :
+    public media::AudioCapturerSource::CaptureCallback,
+    public base::RefCountedThreadSafe<CastReceiverAudioValve> {
+ public:
+  explicit CastReceiverAudioValve(
+      media::AudioCapturerSource::CaptureCallback* cb);
+
+  // AudioCapturerSource::CaptureCallback implementation.
+  void Capture(const media::AudioBus* audio_source,
+               int audio_delay_milliseconds,
+               double volume,
+               bool key_pressed) override;
+  void OnCaptureError() override;
+
+  // When this returns, no more calls will be forwarded to |cb|.
+  void Stop();
+
+ private:
+  friend class base::RefCountedThreadSafe<CastReceiverAudioValve>;
+  ~CastReceiverAudioValve() override;
+  media::AudioCapturerSource::CaptureCallback* cb_;
+  base::Lock lock_;
+};
+
+#endif  // CHROME_RENDERER_MEDIA_CAST_RECEIVER_AUDIO_VALVE_H_