Add support for new bitmapshader context (patchset #5 id:80001 of https://codereview.chromium.org/1757993002/ )"

This reverts commit cd660e1c07371d9cf97824245639b1c0b5ac92fc.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1760123003

Review URL: https://codereview.chromium.org/1760123003
6 files changed