Add new mirror for AppRTC due to code move at GitHub.

This mirror will be replaced by a Chrome infra mirror
as soon as crbug.com/455758 is fixed.

BUG=455758
TESTED=Successfully ran gclient runhooks in a checkout with
the webrtc.DEPS solution added and the old webrtc-samples dir
removed.

Review URL: https://codereview.chromium.org/900403002

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/webrtc/webrtc.DEPS@293976 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
5 files changed