Refactor drawContext/RenderTarget creation
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1914883002

Committed: https://skia.googlesource.com/skia/+/2f1c42e8448bbbadeb3df1c626faa90aa33f8907

Review-Url: https://codereview.chromium.org/1914883002
13 files changed