harfbuzz: Actually apply patch to fix Thai crashes. :-(

      This appears to prevent some renderer crashes that are
fairly easy to trigger with Thai pages on Chrome OS.

(http://codereview.chromium.org/7000012/ previously added
this to chromium.patch, which I mistakenly assumed would get
applied on top of the source during the build process.  I
guess it's instead just a record of our changes from
upstream?)

BUG=chromium:75210,chromium-os:15103
TEST=visited pungame.com/sale.html many times and checked that it no longer triggers a renderer crash

Review URL: http://codereview.chromium.org/7045021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85925 0039d316-1c4b-4281-b951-d872f2087c98