Revert committish 5e8f6d: Add a #define to support building dbus-c++ on older Linux distros

BUG=chromium:151685
TEST=emerge dbus-c++.

Change-Id: Ib81877b9634baea7a58f375f588c055184097383
Reviewed-on: https://chromium-review.googlesource.com/180323
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Tested-by: Lei Zhang <thestig@chromium.org>
diff --git a/src/message.cpp b/src/message.cpp
index 61c0f77..d7ee196 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -33,12 +33,6 @@
 #include "internalerror.h"
 #include "message_p.h"
 
-// TODO(thestig) Remove this once Chromium stops supporting Ubuntu Lucid, where
-// libdbus 1.2.16 does not have DBUS_TYPE_UNIX_FD.
-#ifndef DBUS_TYPE_UNIX_FD
-#define DBUS_TYPE_UNIX_FD      ((int) 'h')
-#endif
-
 using namespace DBus;
 
 /*