Reland "Remove interpolants are inaccurate workaround for Adreno 3xx."

This is a reland of a7a278205bb040061cb4ba46839efe18635c7edc

Clean reland. Change to Chrome screenshot unit test has stuck. The previous
revert of that was the reason this had to be reverted.

Original change's description:
> Remove interpolants are inaccurate workaround for Adreno 3xx.
>
> The chrome screenshot unit test that led to adding this workaround has
> been adjusted to avoid testing AA edges of rendered rectangles. We're
> accepting the inaccuracy in favor of increased performance.
>
> Chrome change: https://chromium-review.googlesource.com/c/chromium/src/+/1129041
>
> Bug: chromium:847984
> Change-Id: I9b714ade2a67e956ebb2773ebe3b8632dc3a50c6
> Reviewed-on: https://skia-review.googlesource.com/140180
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
> Auto-Submit: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

Bug: chromium:847984
Change-Id: I2dc1195f07bb27015b0a7a0fa6263d0e60a32a15
Reviewed-on: https://skia-review.googlesource.com/141761
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
4 files changed