Check to see if Suspending will kill video or audio casted to Chromecast

[thekazian]

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• Extension version: 7.1.6.2
• Browser name & version: Chrome
• Operating system & version: Windows 10

Keep playing HBO GO on a browser tab, and casting it to the TV. Because it's being cast, that tab isn't playing audio or video. I think it uses js to just show the progress slider for the video on the page, and give you the option to pause and a few audio controls. When that tab gets suspended, however, the TV does stop the stream. I'm not sure if we are able to see if current tab is attached to a chromecast session or something like that, I've not worked with chromecast before, but that would be nice.