Processing comments seems to trigger a bug on (some?) Windows systems
due to a negative seek. This CL runs a comment-free version of the
"netrc" file through the parser.

BUG=chromium:664664
TEST=local
  - Uploaded this CL with the change.

Change-Id: I65f5d2f8c1162b3b3a13c66d8becb1cfccf27991
Reviewed-on: https://chromium-review.googlesource.com/411455Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Michael Moss <mmoss@chromium.org>
Commit-Queue: Daniel Jacques <dnj@chromium.org>