[base] Migrate deprecated GrBackendSemaphore methods

See https://skia-review.googlesource.com/c/skia/+/781236 and https://skia-review.googlesource.com/c/skia/+/821978

This is a reland of http://ag/26474115

Change-Id: Ida9996c937b699c46df7f6a945270705879f3416
Bug: b/293490566
1 file changed