Make DBUS an optional dependency so Chromium can be built without it....

chrome/browser/browser_main.cc

Index: chrome/browser/browser_main.cc
===================================================================
--- chrome/browser/browser_main.cc	(revision 77292)
+++ chrome/browser/browser_main.cc	(working copy)
@@ -118,7 +118,9 @@
 #endif
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
+#if defined(USE_DBUS)
 #include <dbus/dbus-glib.h>
+#endif
 #include "chrome/browser/browser_main_gtk.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #endif
@@ -926,10 +928,14 @@
   // definitely harmless, so retained as a reminder of this
   // requirement for gconf.
   g_type_init();
+
+#if defined(USE_DBUS)
   // We use glib-dbus for geolocation and it's possible other libraries
   // (e.g. gnome-keyring) will use it, so initialize its threading here
   // as well.
   dbus_g_thread_init();
+#endif
+
   gfx::GtkInitFromCommandLine(parameters.command_line_);
   SetUpGLibLogHandler();
 #endif