Add check that the PlotLocator's plotIndex is consistent w/ the glyph rect

This verifies that the redundant information w/in the AtlasLocator stays consistent.

Bug: 1056730
Change-Id: Ic76d831c3086cfa85979771e1611853d99031f60
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/282614
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Herb Derby <herb@google.com>
2 files changed