[MiddleOutPolygonTriangulator] Convert pushVertex(p0) to close()
[MiddleOutPolygonTriangulator] Convert pushVertex(p0) to close()

This is the pre-iterator behavior of MiddleOutPolygonTriangulator.
It's slower, but may lead to better triangulations.
We may or may not keep it, depending on Perf's opinion.

Bug: skia:12620
Change-Id: I46f39b551b32af4eebfe8221cbb48a4332db83a8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/468096
Reviewed-by: Michael Ludwig <cb1f3dd24de0f0b611b26bc28bec758a551d9b7d@google.com>
Commit-Queue: Chris Dalton <ef7fc3a08ada7d31f16e9a18b5f3c728256e041e@google.com>

aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia