This changes several CHECK macros textually (but not semantically)
to make them distinguishable by message in crash dumps.

Bug: chromium:855041
Change-Id: I74b66a80c63b264b463eadb333b5359fb412130a
Reviewed-on: https://chromium-review.googlesource.com/1138320Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54482}