Remove dependency on AudioStub in ConnectionToClient

remoting/host/audio_capturer.h

Index: remoting/host/audio_capturer.h
diff --git a/remoting/host/audio_capturer.h b/remoting/host/audio_capturer.h
index c79949903ca892247fae2bcf84b459566dcf366d..5748eb311f410e308bf7fe23e75992465c7222cd 100644
--- a/remoting/host/audio_capturer.h
+++ b/remoting/host/audio_capturer.h
@@ -7,29 +7,19 @@
 
 #include <memory>
 
-#include "base/callback.h"
+#include "remoting/protocol/audio_source.h"
 
 namespace remoting {
 
-class AudioPacket;
-
-class AudioCapturer {
+class AudioCapturer : public protocol::AudioSource {
  public:
-  typedef base::Callback<void(std::unique_ptr<AudioPacket> packet)>
-      PacketCapturedCallback;
-
-  virtual ~AudioCapturer() {}
+  ~AudioCapturer() override {}
 
   // 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();
 
-  // 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);
 };