Revert of Move MutableDataY{,U,V} methods to I420Buffer only. (patchset #14 id:260001 of https://codereview.webrtc.org/2278883002/ )

Reason for revert:
Broke downstream application.

Original issue's description:
> Move MutableDataY{,U,V} methods to I420Buffer only.
>
> Deleted from the VideoFrameBuffer base class.
>
> BUG=webrtc:5921
>
> Committed: https://crrev.com/5539ef6c03c273f39fadae41ace47fdc11ac6d60
> Cr-Commit-Position: refs/heads/master@{#14317}

TBR=perkj@webrtc.org,magjed@webrtc.org,pthatcher@webrtc.org,honghaiz@webrtc.org,stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5921

Review-Url: https://codereview.webrtc.org/2354223002
Cr-Commit-Position: refs/heads/master@{#14325}
27 files changed
tree: 956c58167d65a883cda2715391cbdae297078a14
  1. build_overrides/
  2. chromium/
  3. data/
  4. infra/
  5. resources/
  6. third_party/
  7. tools/
  8. webrtc/
  9. .clang-format
  10. .gitignore
  11. .gn
  12. all.gyp
  13. AUTHORS
  14. BUILD.gn
  15. check_root_dir.py
  16. codereview.settings
  17. DEPS
  18. LICENSE
  19. license_template.txt
  20. LICENSE_THIRD_PARTY
  21. OWNERS
  22. PATENTS
  23. PRESUBMIT.py
  24. pylintrc
  25. README.md
  26. setup_links.py
  27. sync_chromium.py
  28. 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. This page is maintained by the Google Chrome team.

Development

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

More info