Snap alpha for small rects
Snap alpha for small rects

This is more similar to our alpha snapping in AAA.  More critically, we
may have a tiny alpha difference after some 90 degree rotations and that
breaks the Chromium svg layout tests (where the expected reference is a
rotated svg...)

TBR: a8262bf13ea8c26821e91ea9bca6740a77c96dcd@google.com
Bug: skia:
Change-Id: I59b750153488083f65b731643e0baca823cb78e4
Reviewed-on: https://skia-review.googlesource.com/92940
Reviewed-by: Yuqian Li <5537666080209cb36918c342659e07eb122af24c@google.com>
Commit-Queue: Yuqian Li <5537666080209cb36918c342659e07eb122af24c@google.com>

rubenvb/skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,HalCanary/skia-hc,google/skia,rubenvb/skia,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,google/skia,HalCanary/skia-hc,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia