[paulirish]

Unfortunately it doesn't. There is no mechanism right now for the browser to cancel the pushed resources. H2 Push's Cache Digest will introduce this ability, but it's still being designed.

[StavrosK]

Are you sure? SO seems to disagree:

https://stackoverflow.com/questions/29352282/does-the-browse...

And this feature shows as merged into ff56:

https://bugzilla.mozilla.org/show_bug.cgi?id=1367551

Cache digests are about the client telling the server what items it has cached so push doesn't even start, not about canceling pushes.