Relanding: Adding support for Unified Plan offer/answer negotiation to the mediasession layer.

This layer takes in a simplified "options" struct and the current local description,
and generates a new offer/answer. Previously the options struct assumed there would
only be one media description per media type (audio/video), but it now supports
N number of audio/video descriptions.

The |add_legacy_stream| options is removed from the mediasession.cc/.h
in this CL.

The next step is to add the ability for PeerConnection/WebRtcSession to create
"options" to represent multiple RtpTransceivers, and apply the Unified Plan
descriptions correctly. Right now, only Plan B descriptions will be
generated in unit tests.

BUG=chromium:465349

Review-Url: https://codereview.webrtc.org/2991693002
Cr-Original-Commit-Position: refs/heads/master@{#19343}
Committed: https://chromium.googlesource.com/external/webrtc/+/a77e6bbd30276bdc5b30f2cbc1e92ca181ae76f0
Review-Url: https://codereview.webrtc.org/2991693002
Cr-Commit-Position: refs/heads/master@{#19394}
8 files changed
tree: a5e8af9afc219a0c5e3f8adb7a74af974801f274
  1. build_overrides/
  2. data/
  3. infra/
  4. resources/
  5. tools_webrtc/
  6. webrtc/
  7. .clang-format
  8. .git-blame-ignore-revs
  9. .gitignore
  10. .gn
  11. AUTHORS
  12. BUILD.gn
  13. CODE_OF_CONDUCT.md
  14. codereview.settings
  15. DEPS
  16. LICENSE
  17. license_template.txt
  18. LICENSE_THIRD_PARTY
  19. OWNERS
  20. PATENTS
  21. PRESUBMIT.py
  22. pylintrc
  23. README.md
  24. WATCHLISTS
README.md

WebRTC is a free, open software project that provides browsers and mobile applications with Real-Time Communications (RTC) capabilities via simple APIs. The WebRTC components have been optimized to best serve this purpose.

Our mission: To enable rich, high-quality RTC applications to be developed for the browser, mobile platforms, and IoT devices, and allow them all to communicate via a common set of protocols.

The WebRTC initiative is a project supported by Google, Mozilla and Opera, amongst others.

Development

See http://www.webrtc.org/native-code/development for instructions on how to get started developing with the native code.

More info