make strikeToSourceScale consistent through the code

Change-Id: I2ad3493958f71186937efaea6da772523ae7c198
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/469521
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed