Tweak a couple of comments.
Tweak a couple of comments.

Change-Id: I122a6ba8d8286a259b44e4d3bfeebd34404656d6
Reviewed-on: https://code-review.googlesource.com/32190
Reviewed-by: Paul Wankadia <62d4e38bb1380f055ec4b899baa75e52af09c5f7@google.com>

google/re2,google/re2,google/re2,google/re2,google/re2