Remove CommandLine dependency from the Linux's AudioCapturer.

remoting/host/chromoting_host_context.cc

Index: remoting/host/chromoting_host_context.cc
diff --git a/remoting/host/chromoting_host_context.cc b/remoting/host/chromoting_host_context.cc
index 37ba9f3785530db2c6bfca425d11233da8e77ca3..6cdd2be1da27735d40d30698fa516288ccaeff6d 100644
--- a/remoting/host/chromoting_host_context.cc
+++ b/remoting/host/chromoting_host_context.cc
@@ -113,4 +113,15 @@ ChromotingHostContext::url_request_context_getter() {
   return url_request_context_getter_;
 }
 
+#if defined(OS_LINUX)
+FilePath& ChromotingHostContext::audio_capturer_pipe() {
+  return audio_capturer_pipe_;
+}
+
+void ChromotingHostContext::set_audio_capturer_pipe(const FilePath& value) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+  audio_capturer_pipe_ = value;
+}
+#endif  // OS_LINUX
+
 }  // namespace remoting