Adaptation to Skia FontMgr API change

Pass multiple locales to font resolution; handles mixed-language documents which need to know device default language to resolve font fallback correctly.

Depends on https://codereview.chromium.org/670243002/.
    
BUG=422180
R=djsollen@chromium.org,bungeman@chromium.org,dominik.rottsches@intel.com,eae@chromium.org

Review URL: https://codereview.chromium.org/665223004

git-svn-id: svn://svn.chromium.org/blink/trunk@184380 bbb929c8-8fbe-4397-9dbb-9b2b20218538