More SkOffsetSimplePolygon optimizations.
More SkOffsetSimplePolygon optimizations.

* Count edges and prealloc array
* Use first offset for reflex testing rather than recomputing
* Construct list pointers in edge setup array

Bug: skia:
Change-Id: I61a2a6de28a419157c6dad997b0dde0a7999b89e
Reviewed-on: https://skia-review.googlesource.com/145372
Reviewed-by: Robert Phillips <95e8ac5504948c7bf91b22c16a8dbb7ae7c66bfd@google.com>
Commit-Queue: Jim Van Verth <509afb0bfbb23ecaaf1fb3323209f531b45e75a6@google.com>

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