Remove SkBaseDevice::flush (take 2)

Another small step in removing SkCanvas::flush

Change-Id: I6f3bec367e582754b8463b7bfe6a2542436ca829
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/335647
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Adlai Holler <adlai@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
7 files changed