Fix a mismatch in the DBus call issued by RequestVirtualNetworkProperties.

This CL fixes RequestVirtualNetworkProperties in libcros to properly invoke
flimflam.Manager.GetVPNService with a callback to GetServiceGValueNotify
instead of GetPropertiesGValueNotify.

BUG=chromium-os:19951
TEST=gmerge a modified libcros on Cr48 and tested adding a VPN connection via the network menu.

Change-Id: Ia0c30970ea3f8a2f3371251f1a3651dadc9e743a
Reviewed-on: http://gerrit.chromium.org/gerrit/8522
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
1 file changed