Image filters: change applyCropRect() to take a src rect.

Instead of taking the source bitmap and offset, we simply take the
source rect bounds, and make the caller responsible for computing it.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1702683002

Review URL: https://codereview.chromium.org/1702683002
9 files changed