Fix creation of gpu resources in GrThreadSafeViewCache tests

This CL implements and exercises the preference for gpu-generated content.

This CL also switches to drawing a rect (vs. an arrow) since drawing
a concave path on the gpu can be fraught.

Bug: 1108408
Change-Id: Ieec1619b5357ffb31aa74b471ea09c061bd8f74e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319416
Reviewed-by: Adlai Holler <adlai@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
3 files changed