In GrAAConvexPathRenderer use a slightly smaller very large negative float.

This fixes in issue on some mobile gpu's where the larger negative value
caused precision issues when trying to interpolate.

Change-Id: Id76e6f96be2a7e46720794f54c24dafe567c5836
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/284956
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
(cherry picked from commit 1204c4bc3826414e34c8fb93aca7376cbd8fc36c)
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285416
1 file changed