Zhi Huang b2d355ed1f Reland: Reject the description with fewer m= sections.
If the subsequent offer contains fewer m= sections than the existing
description, it would be rejected.

The helper method MediaSectionsInSameOrder is modified and it will
compare the number of m= sections before matching the media type.

The original CL: https://webrtc-review.googlesource.com/c/src/+/9621
Reland it after the web-platform-tests are updated:
https://chromium-review.googlesource.com/c/chromium/src/+/736318

TBR=deadbeef@webrtc.org

Bug: chromium:773620
Change-Id: I60e972eb856efc3cef4a18777791053c9f8e0491
Reviewed-on: https://webrtc-review.googlesource.com/16382
Reviewed-by: Zhi Huang <zhihuang@webrtc.org>
Commit-Queue: Zhi Huang <zhihuang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20455}
2017-10-27 01:07:27 +00:00
..
2017-10-24 16:14:18 +00:00