Fix a bug in the GPU blacklist.  Originally if we fail to collect driver version, we won't apply blacklist logic.  This will fail us to blacklist ATI cards on linux.

BUG=none
TEST=blacklist all ATI cards on linux.
TBR=zmo

Review URL: http://codereview.chromium.org/6532101

git-svn-id: svn://svn.chromium.org/chrome/branches/648/src@75682 0039d316-1c4b-4281-b951-d872f2087c98