When you install and run Chrome from a .dmg, on quit (?) you are asked if you want Chrome to install itself to your Applications folder. The answer to this question (yes/no) should be recorded in UMA. .dmg code lives in chrome/browser/mac/install_from_dmg.mm .

Chrome should also periodically record if it's present in the Dock - perhaps on each launch.

lgrey@ - I think collecting these bits of info should be easy to add. Can you take a look?