To M56: Use ffmpeg for opus decoding, no need to maintain our decoder.
As a bonus this allows WebAudio to start using opus.
BUG=482934
TEST=all opus tests pass with the previous expectations.
Review-Url: https://codereview.chromium.org/2435603009
Cr-Commit-Position: refs/heads/master@{#433433}
(cherry picked from commit 655b0cf987eca28d8035cb3ceb1af6c4b916b179)
TBR=dalecurtis@chromium.org,avi@chromium.org,alokp@chromium.org
Review URL: https://codereview.chromium.org/2543633006 .
Cr-Commit-Position: refs/branch-heads/2924@{#259}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}
16 files changed
