[chromium] run-webkit-tests can't work on ubuntu 12.04

[chromium] run-webkit-tests can't work on ubuntu 12.04
https://bugs.webkit.org/show_bug.cgi?id=86565

Patch by Li Yin <li.yin@intel.com> on 2012-05-17
Reviewed by Kent Tamura.

On ubuntu 12.04, the package ttf-thai-tlwg install the Garuda.ttf
into /usr/share/fonts/truetype/tlwg/Garuda.ttf, not /usr/share/fonts/truetype/thai/Garuda.ttf

* DumpRenderTree/chromium/TestShellLinux.cpp:
(checkAndLoadFontFile):
(setupFontconfig):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@117446 268f45cc-cd09-0410-ab3c-d52691b4dbfc