Extract a GrVertexChunkArray class with a builder

This will be used by the new stroke tessellator. All the other
tessellators should start chopping and chunking too. That will allow us
to quit cropping paths if we are afraid they might need more segments
than are supported.

Bug: chromium:1172543
Change-Id: I30f0ebb581f56cac099d8c05e0e181c4657c3db8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/390096
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
14 files changed