SkPaint: clean up ctor, dtor, etc

Change-Id: I5a333112f68fcd001f39e646570a246875c03bc3
Reviewed-on: https://skia-review.googlesource.com/c/191566
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
2 files changed