Android 9.0.0 release 42
[automerger] libwebm: Cherrypick 5a41830 from upstream am: 0f99871368 am: 6b040ab5b6 am: 9a316baf5e am: 6cf161e924 am: 76f6b3b052 am: 76a6584c78 am: 1595703ea2
am: 7934cd0a7e

Change-Id: If0430ac51e728017b644132a3c6c80353c2cf175