Google mostly works at HEAD. Very little is versioned, and branches are almost unheard of. In general you change the much depended on library and all of its co

Google mostly works at HEAD. Very little is versioned, and branches are almost unheard of. In general you change the much depended on library and all of its consumers (probably over time in multiple changes, but you can do it in one go if it really needs to be a single giant change).