Update linux host to handle SIGHUP. use it to reload config.

remoting/host/posix/sighup_listener.h

Index: remoting/host/posix/sighup_listener.h
diff --git a/remoting/host/sighup_listener_mac.h b/remoting/host/posix/sighup_listener.h
similarity index 64%
rename from remoting/host/sighup_listener_mac.h
rename to remoting/host/posix/sighup_listener.h
index a0687594fde22a274f565a77095b15a51450c48b..48140a39f9a4460bcf877dae949822ec64f2a3cb 100644
--- a/remoting/host/sighup_listener_mac.h
+++ b/remoting/host/posix/sighup_listener.h
@@ -3,11 +3,11 @@
 // found in the LICENSE file.
 //
 // This file implements a signal handler that is used to safely handle SIGHUP
-// and trigger the specified callback. It is currently used on Mac in order to
-// reload the me2me host configuration, but would need minimal changes on Linux.
+// and trigger the specified callback. It is used on Linux and Mac in order to
+// reload the me2me host configuration.
 
-#ifndef REMOTING_HOST_SIGHUP_LISTENER_MAC_H_
-#define REMOTING_HOST_SIGHUP_LISTENER_MAC_H_
+#ifndef REMOTING_HOST_POSIX_SIGHUP_LISTENER_H_
+#define REMOTING_HOST_POSIX_SIGHUP_LISTENER_H_
 
 #include "base/callback_forward.h"
 
@@ -19,4 +19,4 @@ bool RegisterHupSignalHandler(const base::Closure& callback);
 
 }  // namespace remoting
 
-#endif  // REMOTING_HOST_SIGHUP_LISTENER_MAC_H_
+#endif  // REMOTING_HOST_POSIX_SIGHUP_LISTENER_H_