More than that, you have to "install" the code for every webapp that you use at least once (unless it's cached).
How do you differentiate between download and install? Is self-modifying code repeatedly installing itself?
There's no good distinction, but given that browsers have caches, I think there's at least a very blurry line there.
Then perhaps the distinction should be the programs called 'Windows installer' type in Explorer that TFA is talking about and not a blanket inclusion of all software that isn't ASM written on the device running it.