GitLab

Just a minor clean up to some of the internal drawing/prep functions
that don't actually modify SkiaRenderer itself.

CalculateRPDQParams cannot be const because it needs to create
ScopedSkImageBuilders, which don't work with const SkiaRenderer*'s.

Bug: 1013735
Change-Id: Ic3bddd6cea28dfaf4b977ebef77e1ced4eea6089
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863629
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: weiliangc <weiliangc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712669}