[Reland] Repeating SkBitmapProcState rounding bias

[Reland] Repeating SkBitmapProcState rounding bias

1) observe the bias in repeat matrix procs also.
2) add utility for device space -> bitmap space mapping.
3) remove unneeded filter bias

This is a reland of https://codereview.chromium.org/1529833003/. The
main difference (and the fix) vs. the prev version is increased
precision: the mapper now operates with SkFractionalInts.

R=reed@google.com
BUG=skia:4680, skia:4649
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1539083002

Review URL: https://codereview.chromium.org/1539083002