Enable new Skia bitmap font handling on Windows

Enable the new, improved, bitmap font rendering code path in the Skia
DirectWrite backend on windows. This will improve the rendering of
certain system fonts, most notable Courier New.

BUG=356823
R=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/310753004

git-svn-id: svn://svn.chromium.org/blink/trunk@175390 bbb929c8-8fbe-4397-9dbb-9b2b20218538