Stop overflow of windows rects in GrClipStack

Bug: skia:10989
Change-Id: I512ccbd3d95178756ae436f7c67ed53d46105ae7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/339165
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
6 files changed