Support audio output device enumeration and selection in PPAPI

ppapi/thunk/ppb_audio_output_api.h

Index: ppapi/thunk/ppb_audio_output_api.h
diff --git a/ppapi/thunk/ppb_audio_output_api.h b/ppapi/thunk/ppb_audio_output_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..4fceee757d1111435411bd49dd1615b2dfd2db71
--- /dev/null
+++ b/ppapi/thunk/ppb_audio_output_api.h
@@ -0,0 +1,43 @@
+// Copyright (c) 2017 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 PPAPI_THUNK_AUDIO_OUTPUT_API_H_
+#define PPAPI_THUNK_AUDIO_OUTPUT_API_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/memory/ref_counted.h"
+#include "ppapi/c/dev/ppb_audio_output_dev.h"
+
+namespace ppapi {
+
+class TrackedCallback;
+
+namespace thunk {
+
+class PPB_AudioOutput_API {
+ public:
+  virtual ~PPB_AudioOutput_API() {}
+
+  virtual int32_t EnumerateDevices(const PP_ArrayOutput& output,
+                                   scoped_refptr<TrackedCallback> callback) = 0;
+  virtual int32_t MonitorDeviceChange(PP_MonitorDeviceChangeCallback callback,
+                                      void* user_data) = 0;
+  virtual int32_t Open(PP_Resource device_ref,
+                       PP_Resource config,
+                       PPB_AudioOutput_Callback audio_output_callback,
+                       void* user_data,
+                       scoped_refptr<TrackedCallback> callback) = 0;
+  virtual PP_Resource GetCurrentConfig() = 0;
+  virtual PP_Bool StartPlayback() = 0;
+  virtual PP_Bool StopPlayback() = 0;
+  virtual void Close() = 0;
+};
+
+}  // namespace thunk
+}  // namespace ppapi
+
+#endif  // PPAPI_THUNK_AUDIO_OUTPUT_API_H_