Remove subpixel positioning from the atlas path renderer key

Descretizing subpixel matrix translates into 4 values for a path key had
some pretty serious bugs:

  * Different round-out behavior in the range of translates that all
    mapped to the same subpixel position causing us to mis-place the
    mask.

  * Different round-out behavior in the range of translates that all
    mapped to the same subpixel position causing us to transpose
    differently.

Ideally we will address these issues, but given the urgency for M95 we
will first tear it out entirely. The exact translation matching in this
CL still solves the clipping problem, which was the original motivation
for the cache.

Bug: chromium:1253952
Change-Id: I62409614733c5e9ab77ba11c4de7e40495c07453
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/456156
Auto-Submit: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
2 files changed