Remove CommandLine dependency from the Linux's AudioCapturer.

remoting/host/audio_capturer_linux.h

Index: remoting/host/audio_capturer_linux.h
diff --git a/remoting/host/audio_capturer_linux.h b/remoting/host/audio_capturer_linux.h
index c85beb3a2c62064874cb1c8cbb5f6007086cd1b3..8a825fffbf0b3fee922c56d750c7e7d4e0caf9a6 100644
--- a/remoting/host/audio_capturer_linux.h
+++ b/remoting/host/audio_capturer_linux.h
@@ -18,6 +18,10 @@ namespace remoting {
 class AudioCapturerLinux : public AudioCapturer,
                            public MessageLoopForIO::Watcher {
  public:
+  // Must be called to configure the capturer before the first instance is
+  // created.
+  static void SetPipeName(const FilePath& pipe_name);
+
   explicit AudioCapturerLinux(const FilePath& pipe_name);
   virtual ~AudioCapturerLinux();