This is the linux side of the fix given in r46417.
Basically, r46388 introduced a function FontPlatformData::description() that doesn't exist in the various chromium platform-specific versions of this file.
r46417 fixed windows. This will fix Linux. Mac doesn't seem to be affected.
Created attachment 33568 [details]
Trivial implemenation of FontPlatformData::description()
Commited as http://trac.webkit.org/changeset/46426