Fix issues related to resolving fonts based on name.

1) non-system font files are not added to the cache.
2) We cache the default fonts for quick lookup.

Review URL: https://codereview.chromium.org/16439004

git-svn-id: http://skia.googlecode.com/svn/trunk@9441 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed