Add RTCConfiguration getter and setter methods. The immediate plan is to move some flags into an embedded MediaConfig (https://codereview.webrtc.org/1818033002/), which will be possible after Chrome is updated to use these new setter methods.

BUG=webrtc:4906
R=hbos@google.com, hbos@webrtc.org, perkj@webrtc.org, pthatcher@webrtc.org

Review URL: https://codereview.webrtc.org/1836083003 .

Cr-Original-Commit-Position: refs/heads/master@{#12177}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 71bdda0ededda74cdd73a8309419cf626499627f
2 files changed