Landing these in WebRTC under a guard so they don't build in
Chromium. The guard can be removed once Chromium has migrated to use the
new GN targets.
BUG=webrtc:6081
NOTRY=true
Review-Url: https://codereview.webrtc.org/2117183005
Cr-Commit-Position: refs/heads/master@{#13397}