chromium: conditionally compile routines for use with GLIB

The routine QuoteArgForDesktopFileExec is only called when GLIB is
used, and compilation will fail with the following error message
if it is compiled without GLIB support (e.g. under Wayland):
	"defined but not used [-Werror=unused-function]"

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>