Roll chromium_revision a8e5140..c6076f2 (372922:372974) incl. update to Opus v.1.1.2

Includes updates to tests for Opus v.1.1.2, reveiwed in
https://codereview.webrtc.org/1629413002/

Change log: https://chromium.googlesource.com/chromium/src/+log/a8e5140..c6076f2
Full diff: https://chromium.googlesource.com/chromium/src/+/a8e5140..c6076f2

Changed dependencies:
* src/third_party/catapult: https://chromium.googlesource.com/external/github.com/catapult-project/catapult.git/+log/471db30..d4d48e6
* src/third_party/opus/src: https://chromium.googlesource.com/chromium/deps/opus.git/+log/cae6961..655cc54
DEPS diff: https://chromium.googlesource.com/chromium/src/+/a8e5140..c6076f2/DEPS

No update to Clang.

BUG=chromium:580524
TBR=

Review URL: https://codereview.webrtc.org/1657343002

Cr-Original-Commit-Position: refs/heads/master@{#11464}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: c3a0983d4bedea07b6d1a74dc165b56fca590e82
5 files changed