GitLab

NULL is obsolete and doesn't work with the upcoming CheckedPtr,
so rewrites NULL to nullptr.

Change-Id: If1e2a15c95611157317aac48176d1cdbf3f23251
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2633487Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844926}