CSVTable should only understand CRLF and LF as EOL

So far, CSVTable understood any combination of CR and LF characters as
the end of line. After a discussion linked to in
https://crbug.com/923811, this CL changes that to explicitly only
allowing CRLF and LF.

Moreover, CRLF is no longer converted to LF inside quoted (escaped)
strings.

Performance impact, as measured with the benchmark from
https://crrev.com/c/1459642:
 * Run time of the benchmark decreased from about 10s to about 9.5s
 * Peak memory consumption over 5 runs decreased from about 168700 kB
   to about 168350 kB

Bug: 923811
Change-Id: I979d05e9f296f285db99dc22662bae29c907ea2a
Reviewed-on: https://chromium-review.googlesource.com/c/1461042
Commit-Queue: Vaclav Brozek <vabr@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630708}
3 files changed