Isn't that been closed down though?
Motorola shutters U.S. factory as costs outweigh gains | BGR
I guess the Nexus 6 is very likely to be made in China, by Foxconn quite possibly. They're by far the largest OEM that takes on this sort of work, including Apple, Microsoft(Xbox), Sony(Playstation), HP and Dell.
Don't think it's been approved yet, Lenovo are buying Motorola from Google. And I'm sure we all know where Lenovo comes from. They make all their phones in Xiamen and laptops are made in Beijing. What are Lenovo's plans for Motorola? Will they absorb them (assimilate them Borg style), or keep Motorola going as a subsidiary? It's not the first time that Lenovo bought a large and important US business, IBM's PC and laptop division, the inventors of the PC.
Lenovo are a huge phone manufacturer as well as PC manufacturer, but don't any North American presence at all for phones. Motorola are a famous brand in North America of course. Maybe they just want the brand as a way into the that important market. Happened in the past of course with TVs, many used to be made in America, e.g. RCA, Magnavox, Sylvania, all now made by Changhong, TCL, Haier, Konka, etc.