poll_write_buf landed but comment and other issue says "being waited on"

[FrankReh]

Version
In latest master, 1.0 rc1+

Platform
Just in the source. Not a runtime problem.

Description
Was reading through hyper code, finding everything well organized and very few TODOs. Found a TODO from years ago and now its reason seems outdated. As 1.0 is about to be released, thought someone might want to revisit. Maybe it's as simple as the comment being changed. Sorry I'm in no position to suggest a PR as I don't know enough about the implications of the change one way or the other.

hyper/src/proto/h1/io.rs

Lines 304 to 307 in 96dcc79

	// TODO(eliza): we have to do this manually because
	// `poll_write_buf` doesn't exist in Tokio 0.3 yet...when
	// `poll_write_buf` comes back, the manual advance will need to leave!
	self.write_buf.advance(n);

This closed item #2317 also said there should be a change back once the feature had landed in tokio. It seems to have landed in tokio 0.5.1 and appears to me to still be there.

(How do I remove the bug label?)