Add a use counter for RtcpMuxPolicy of "negotiate".

Add a use counter for RtcpMuxPolicy of "negotiate".

When parsing the RTCConfiguration, if the RtcpMuxPolicy is "negotiate",
it will be counted. The number will be used to estimate the risk of
removing this feature.

Intent to deprecate thread: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/OP2SGSWF5lo

BUG=chromium:685727
Review-Url: https://codereview.chromium.org/2679093006
Cr-Commit-Position: refs/heads/master@{#451162}
(cherry picked from commit 887a0d5ac980c21eebecb133a75e08dc2fe048bf)

Review-Url: https://codereview.chromium.org/2733583002 .
Cr-Commit-Position: refs/branch-heads/2987@{#749}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/43cca2fb095873d29c99b19947c6dc867fa0c884

[foolip, 2017-03-03 15:25:48]

Description was changed from

==========
Add a use counter for RtcpMuxPolicy of "negotiate".

When parsing the RTCConfiguration, if the RtcpMuxPolicy is "negotiate",
it will be counted. The number will be used to estimate the risk of
removing this feature.

Intent to deprecate thread:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/OP2SGSWF5lo

BUG=chromium:685727

Review-Url: https://codereview.chromium.org/2679093006
Cr-Commit-Position: refs/heads/master@{#451162}
(cherry picked from commit 887a0d5ac980c21eebecb133a75e08dc2fe048bf)
==========

to

==========
Add a use counter for RtcpMuxPolicy of "negotiate".

When parsing the RTCConfiguration, if the RtcpMuxPolicy is "negotiate",
it will be counted. The number will be used to estimate the risk of
removing this feature.

Intent to deprecate thread:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/OP2SGSWF5lo

BUG=chromium:685727

Review-Url: https://codereview.chromium.org/2679093006
Cr-Commit-Position: refs/heads/master@{#451162}
(cherry picked from commit 887a0d5ac980c21eebecb133a75e08dc2fe048bf)

Review-Url: https://codereview.chromium.org/2733583002 .
Cr-Commit-Position: refs/branch-heads/2987@{#749}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/43cca2fb095873d29c99b19947c6...
==========

[foolip, 2017-03-03 15:25:49]

Committed patchset #1 (id:1) manually as
43cca2fb095873d29c99b19947c6dc867fa0c884.