CHICAGO — Revolution Brewing and Garrett Popcorn have been neighbors under the same roof for nine years, and that has led to the inevitable: a Revolution beer made with Garrett popcorn. When the process began in January, the idea of what to do — brown ale made with Garrett’s renowned CaramelCrisp — came quickly. But how to do it took some time. Revolution added different sorts of popcorn to the brewing process. It considered different ingredients used in Garrett’s caramel corn. It tried sweetening the beer with various caramel flavors. It tinkered with about a dozen trials, but landed in a sim…