For security and privacy, change http://www.chromium.org/developers/contributing-code
link to use HTTPS.

R=dpranke@chromium.org

Bug:
Change-Id: I12d0658631d7704de1b3072f6eb840814cc6bed0
Reviewed-on: https://chromium-review.googlesource.com/702034Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>