headless: Make it possible to override the DevTools server address

Make it possible to override the address at which the DevTools server
accepts for incoming connections. This address is the loopback interface
by default, but with this switch it can be configured to be any IP
address.

TEST=headless_shell --remote-debugging-address=0.0.0.0 --remote-debugging-port=9222

Review URL: https://codereview.chromium.org/1920773003

Cr-Commit-Position: refs/heads/master@{#389743}
3 files changed