simplify drawingType calculation

Simplify determining which method used to draw text. This will make
inlining it into the processGlyphRun code easier.

Bug: chromium:1280180

Change-Id: I69241a9c198904334c012ab301e80d0cf9fd45d0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/491437
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed