What steps will reproduce the problem?
(1) Running mojo media application from browser process
(2) Create its own IO thread for IO work

What is the expected output?
Be able to use IO thread to run its own mojo media app, start/stop

What do you see instead?
Because the original thread is not IO, it will hit asserts on ThreadRestrictions::AssertIOAllowed() when the IO thread stops.
Set mojo app to use its own thread and create IO thread later on has same assert.

I need to set the thread that running mojo_media_application to SetIOAllowed(true)
Not sure if this is by design