Linux: make it possible to build with third_party/xdg-utils directory removed
Linux: make it possible to build with third_party/xdg-utils directory removed

This is useful for Linux distributions that remove third party directories
to ensure that the bundled versions will not be used.

In fact, this is upstreaming a Gentoo Linux patch.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/6282005

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@71672 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser