Remove DISALLOW_COPY_AND_ASSIGN from net/base/*.

Also fix lint errors; no functional change

Bug: 1010217
Change-Id: I3e4af6d594f34b9717d2a96a8f14f3bd6c90e318
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2516881


Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: David Bienvenu <davidbienvenu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824880}