Pause Wuffs' getFrameCount in incremental decode

Bug: skia:8235
Bug: skia:8750
Change-Id: I7b8a6a1aba38ba2f16bd184253fbef2a37000cef
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/223016
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
2 files changed