SkPDF: use sk_ref_sp

    s/sk_sp<[^>]*>(SkRef(\([^)]*\)))/sk_ref_sp(\1)/

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1777923002

Review URL: https://codereview.chromium.org/1777923002
7 files changed