Remove dependency on AudioStub in ConnectionToClient

remoting/protocol/audio_source.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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.
 
-#ifndef REMOTING_HOST_AUDIO_CAPTURER_H_
-#define REMOTING_HOST_AUDIO_CAPTURER_H_
+#ifndef REMOTING_PROTOCOL_AUDIO_SOURCE_H_
+#define REMOTING_PROTOCOL_AUDIO_SOURCE_H_
 
 #include <memory>
 
 #include "base/callback.h"
 
 namespace remoting {
 
 class AudioPacket;
 
-class AudioCapturer {
+namespace protocol {
+
+class AudioSource {
  public:
   typedef base::Callback<void(std::unique_ptr<AudioPacket> packet)>
       PacketCapturedCallback;
 
-  virtual ~AudioCapturer() {}
-
-  // Returns true if audio capturing is supported on this platform. If this
-  // returns true, then Create() must not return nullptr.
-  static bool IsSupported();
-  static std::unique_ptr<AudioCapturer> Create();
+  virtual ~AudioSource() {}
 
   // Capturers should sample at a 44.1 or 48 kHz sampling rate, in uncompressed
   // PCM stereo format. Capturers may choose the number of frames per packet.
   // Returns true on success.
   virtual bool Start(const PacketCapturedCallback& callback) = 0;
-
-  static bool IsValidSampleRate(int sample_rate);
 };
 
+}  // namespace protocol
 }  // namespace remoting
 
-#endif  // REMOTING_HOST_AUDIO_CAPTURER_H_
+#endif  // REMOTING_PROTOCOL_AUDIO_SOURCE_H_