Reland of https://codereview.webrtc.org/2044523002.

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-Original-Commit-Position: refs/heads/master@{#13397}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 1d4fefbbaf056492096e9e8a689550c6b7c49fe9
4 files changed