limit mask drawing to clip bounds
limit mask drawing to clip bounds

Change-Id: Iab74531614654f241e12d1cd1af14725888580c8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/207143
Reviewed-by: Mike Reed <f5cabf8735907151a446812c9875d6c0c712d847@google.com>
Auto-Submit: Lee Salzman <5baebf001b4c74159c9f764651b8311e9a0ca3c4@mozilla.com>
Commit-Queue: Mike Klein <14574f09dfa9b4e14759b88c3426a495a0e627b0@google.com>

aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,rubenvb/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,google/skia,rubenvb/skia,google/skia,HalCanary/skia-hc,rubenvb/skia,rubenvb/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,rubenvb/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,google/skia,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc