Move remoting::GetUsername() from remoting/base to remoting/host

remoting/host/username.h

Index: remoting/host/username.h
diff --git a/remoting/host/username.h b/remoting/host/username.h
new file mode 100644
index 0000000000000000000000000000000000000000..28fc2ae28f23b583a87cb42a520202359cbe99af
--- /dev/null
+++ b/remoting/host/username.h
@@ -0,0 +1,18 @@
+// Copyright 2013 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_USERNAME_H_
+#define REMOTING_HOST_USERNAME_H_
+
+#include <string>
+
+namespace remoting {
+
+// Returns the username associated with this process, or the empty string on
+// error or if not implemented.
+std::string GetUsername();
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_USERNAME_H_