Allow distance field path renderer to store bitmaps at low resolutions

BUG=chromium:682918

Change-Id: I1a0608f7e6394ab05eebc4b78fb7087ca718f617
Reviewed-on: https://skia-review.googlesource.com/8971
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
4 files changed