I believe that you are making a distinction without a difference. Operating over extremely short timeframes is what allows electronic traders to provide such efficient pricing.
http://blogmaverick.com/2014/04/03/the-idiots-guide-to-high-...
In my experience though, electronic market making, which I regard as a very good thing, is a direct subset of HFT. To do it properly you must be fully automated, fast, across venue and trade alot. By nearly every definition I've seen that makes you HFT.