A Mozilla developer ran the µmix static analyzer on its codebase and incidentally found some issues regarding null checks in Skia. This fixes the issues that were found.

Downstream bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1278452

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2046563007

Review-Url: https://codereview.chromium.org/2046563007
3 files changed