What is the technical name of the electric window dimming system?
From a Boeing article:


  Electro-chromatic dimmable windows


It's generically described in the article as being an electronically controlled and can dim or lighten the cabin at the push of a button. They claim 70k cycles or 20 years of service

Gizmodo provides a succinct description of it's operation


  The dimming effect is the result of an electrified gel sandwiched between two thin pieces of glass. As the electric current increases, the gel darkens and as it drops, the gel lightens.


The maker appears to be Gentex and they have a variety of electric dimming window patents but it's not clear which one is used in the 787