Don't use drawVertices for blur masks

Total DMSAA Multisample Render Passes: 190 -> 110

Bug: skia:11396
Change-Id: I721de497f497c40e854d219829e853765e2dc778
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/404856
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed