Fix AudioCapturer implementation to read from audio pipe even when there are no active clients.

remoting/host/audio_capturer_linux.h

 // Copyright (c) 2012 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_LINUX_H_
 #define REMOTING_HOST_AUDIO_CAPTURER_LINUX_H_
 
+#include "base/memory/ref_counted.h"
 #include "remoting/host/audio_capturer.h"
-
-#include "base/message_loop.h"
-#include "base/time.h"
-#include "base/timer.h"
+#include "remoting/host/linux/audio_pipe_reader.h"
 
 class FilePath;
 
 namespace remoting {
 
+// Linux implementation of AudioCapturer interface which captures audio by
+// reading samples from a Pulseaudio "pipe" sink.
 class AudioCapturerLinux : public AudioCapturer,
-                           public MessageLoopForIO::Watcher {
+                           public AudioPipeReader::StreamObserver {
  public:
-  // Must be called to configure the capturer before the first instance is
-  // created.
-  static void SetPipeName(const FilePath& pipe_name);
+  // Must be called to configure the capturer before the first capturer instance
+  // is created. |task_runner| is an IO thread that is passed to AudioPipeReader
+  // to read from the pipe.
+  static void InitializePipeReader(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      const FilePath& pipe_name);
 
-  explicit AudioCapturerLinux(const FilePath& pipe_name);
+  explicit AudioCapturerLinux(
+      scoped_refptr<AudioPipeReader> pipe_reader);
   virtual ~AudioCapturerLinux();
 
   // AudioCapturer interface.
   virtual bool Start(const PacketCapturedCallback& callback) OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual bool IsStarted() OVERRIDE;
 
-  // MessageLoopForIO::Watcher interface.
-  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
-  virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
+  // AudioPipeReader::StreamObserver interface.
+  virtual void OnDataRead(scoped_refptr<base::RefCountedString> data) OVERRIDE;
 
  private:
-  void StartTimer();
-  void DoCapture();
-  void WaitForPipeReadable();
-
-  int pipe_fd_;
-  base::RepeatingTimer<AudioCapturerLinux> timer_;
+  scoped_refptr<AudioPipeReader> pipe_reader_;
   PacketCapturedCallback callback_;
 
-  // Time when capturing was started.
-  base::TimeTicks started_time_;
-
-  // Stream position of the last capture.
-  int64 last_capture_samples_;
-
-  // Bytes left from the previous read.
-  std::string left_over_bytes_;
-
-  MessageLoopForIO::FileDescriptorWatcher file_descriptor_watcher_;
-
   DISALLOW_COPY_AND_ASSIGN(AudioCapturerLinux);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_AUDIO_CAPTURER_LINUX_H_