Add CHECKs to debug null pointer crash in LinkHighlightImpl::Paint

Bug: 1016587
Change-Id: Ie28c2f0f608d9929ff00a65c56ad31166356bbba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1950730
Commit-Queue: Philip Rogers <pdr@chromium.org>
Auto-Submit: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722086}
1 file changed