Host-side implementation of ARC audio bridge.

components/arc/common/audio.mojom

+// Copyright 2016 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.
+
+module arc;
+
+// Use same switch values as kernel switch events.
+[Extensible]
+enum AudioSwitch {
+  SW_HEADPHONE_INSERT = 0x02,
+  SW_MICROPHONE_INSERT = 0x04
+};
+
+interface AudioInstance {
+  // Notify plug states of headphone, microphone, etc.  Each switch state is
+  // represented by the corresponding bit, if the bit is set then the switch
+  // is plugged/inserted.
+  NotifySwitchState(uint32 state);
+};