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.
The article should make that clear right at the start. I read the whole thing and came away with the strong impression that these things were Chrome-only (apart from the one mention of Firefox).
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.