Remove using Settings for SkTextBlobCacheDiffCanvas

This is change 2/2. Remove the unused Settings structure.

Chrome change:
https://chromium-review.googlesource.com/c/chromium/src/+/1758438

Part 1:
https://skia-review.googlesource.com/c/skia/+/235102

Change-Id: Ib5d2ed1a18ae904c7d1eeffc18b5c69ab04c5f92
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/235858
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
2 files changed