Fix Gn untracked headers in webrtc/media

BUG=webrtc:7645

Review-Url: https://codereview.webrtc.org/3013063002
Review-Url: https://codereview.webrtc.org/3018473002
Cr-Original-Commit-Position: refs/heads/master@{#19844}
Cr-Original-Original-Commit-Position: refs/heads/master@{#19824}
Cr-Mirrored-From: https://webrtc.googlesource.com/src
Cr-Mirrored-Commit: 6674846b4adc999f69bfdb12080749d4e4ab729d
1 file changed