Some libwebrtc-specific files are guarded with ENABLE(WEB_RTC) instead of USE(LIBWEBRTC).
Created attachment 450323 [details] Patch
Committed r288790 (246567@main): <https://commits.webkit.org/246567@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 450323 [details].
<rdar://problem/88224144>