I assume these are all currently non-standard APIs that Firefox will nonetheless be expected to implement? Does Firefox ever force work on the Blink team, or it is it only ever the other way around?
Getting the features into the spec is the vast majority of the work. Though some features are not yet implemented in Firefox or Safari, they have both indicated their intention to do so.
Cue in "bad browsers don't implement APIs" in 3... 2... 1...