Implement support for fake bold/italics for non-GDI windows font path

Add plumbing for fake bold/italics to the windows non-GDI font path
and pass the values along to skia.

BUG=249099
R=bungeman@chromium.org, schenney@chromium.org

Review URL: https://codereview.chromium.org/24609002

git-svn-id: svn://svn.chromium.org/blink/trunk@158380 bbb929c8-8fbe-4397-9dbb-9b2b20218538