Normalize vectors in dot product for quad type calculations.

Bug: skia:
Change-Id: Icb840daf1fd31afdeed387486db54283bb5b85f3
Reviewed-on: https://skia-review.googlesource.com/c/180640
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
1 file changed