KURL::Port(): Remove unneeded constants

Remove the constants kMaximumValidPortNumber and kInvalidPortNumber from
kurl.cc as they are confusing and don't actually do anything.

Also change remaining CHECKs in KURL::Port back to DCHECKs now that we
have confidence the change is safe.

Also make the method comment less confusing.

BUG=606462

Change-Id: I4719b8611cc6f3f0c5f488d8c86f3b6b8ad6d88f
Reviewed-on: https://chromium-review.googlesource.com/1127083
Commit-Queue: Adam Rice <ricea@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575942}
2 files changed