Bug
1853057 - use the cached remote result to anwser the support information. r=jolin
When asking config in the content process, we should return result based
on the cached result in the remote decoder because we don't want
to run Windows Media Foundation (WMF) in the content process, which
should be better to run only in the higher security sandboxed process.
We use that function in [1] in the content process to indentify what
types the media engine supports.
[1] https://searchfox.org/mozilla-central/rev/
b6cd901cf074c5e75e3902d660bafa3cf3967c40/dom/media/ExternalEngineStateMachine.cpp#332-337
Differential Revision: https://phabricator.services.mozilla.com/
D187522