Remove the marshal generation code.

Starting from GLib version 2.29.12, it's not required to provide a
marshaller function when receiving and sending signals over DBus since
the default works with all the basic types.

This was introduced in the following changes in GLib:

 * https://git.gnome.org/browse/glib/commit/?id=88ab35f3cb6127036361e421987a127bddb989c8
 * https://git.gnome.org/browse/glib/commit/?id=fa2861e3b6109e002b68aa105b5ecbcba88724c1

BUG=None
TEST=unittest and manual test.

Manual test procedure:
* update_engine_client sends the method request for updating and gets
  the signal sent by update_engine on dbus_service.cc

Change-Id: Id13b45cb4191dcfb9cab371b82bb589c132c7e09
Reviewed-on: https://chromium-review.googlesource.com/186384
Reviewed-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/dbus_service.cc b/dbus_service.cc
index cbfdc17..f75823c 100644
--- a/dbus_service.cc
+++ b/dbus_service.cc
@@ -14,7 +14,6 @@
 #include "update_engine/connection_manager.h"
 #include "update_engine/dbus_constants.h"
 #include "update_engine/hardware_interface.h"
-#include "update_engine/marshal.glibmarshal.h"
 #include "update_engine/omaha_request_params.h"
 #include "update_engine/p2p_manager.h"
 #include "update_engine/prefs.h"
@@ -100,7 +99,7 @@
       0,  // 0 == no class method associated
       NULL,  // Accumulator
       NULL,  // Accumulator data
-      update_engine_VOID__INT64_DOUBLE_STRING_STRING_INT64,
+      NULL,  // Marshaller
       G_TYPE_NONE,  // Return type
       5,  // param count:
       G_TYPE_INT64,