It probably is chromed plastic. Some trim is chromed metal, like door handles, for durability. One way to check? Use a magnet.
Dodge used chrome plastic on hub caps or inserts on their truck wheels. Who would have thunk?!
Caring for this chrome plastic can be challenging. The chrome plating on plastic is very thin and tends to flake off in time. Even though chrome is supposedly a very hard metal plating, it can be scratched if not cleaned properly. I would be careful (not recommend) about using a true chrome cleaner that is abrasive. I would go with a mild metal polish, like SimiChrome, Flitz, or MAAS. I`ve used Optimum`s Metal Polish and that works good for dirty chromed plastic. Just do not rub real hard. I use a swede-type (low nap) microfiber for application and removal. Some like Klasse All-In-One (KAIO) for cleaning chromed plastic, as it is a chemical cleaner and not abrasive and will offer some protection as a sealant, but I have not used it for that. The Rag Company makes a microfiber cloth specifically for metal polishing.
On a similar note, chromed plastic on the interior of vehicles, like control knobs or switches or dash instrument gauge bezel rings, can be polished with the above mentioned metal polishes or KAIO applied judiciously (AKA, sparingly and lightly) with a cotton swab (AKA Q-Tip) and removed with clean cotton swab or suede microfiber. Cleaned and polished chrome-accented trim just stands out in an interior and it is one of the last things I do in an interior.
One BIG word of caution is not to use Stoner`s Tarminator on plastic grills to remove bugs. The solvents can literally dissolve older plastics. Not all plastics from various vehicle manufacturers are susceptible to this, but one bad experience has me a little gun-shy on using it on grills. Poor Boy`s Bug Squash is a much safer solution (literally!).