`ImageDecoder` is `[SecureContext]` but related interfaces aren't

[padenot]

We noticed this while implementing, it's a bit unusual, ImageTrack and ImageTrackList are exposed on non-secure context. Reading the old PR, I didn't manage to find a particular reason, maybe it's just an oversight?

[alvestrand]

Fingerprint surface?

[dalecurtis]

Just an oversight. I'll mark them as SecureContext in Chrome and hope that doesn't break anything.