Moved RTAdjust into ThreadContext

Change-Id: I3b53b710237a6866097442272f8f3380a9e7a868
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/458724
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
7 files changed