Chicken hearts, gizzards, livers and often intestines, usually sold together. In Chongqing they are stir-fried with pickled chili, and they go into Sichuan hotpot.
At the wet market there's a stall just for chicken giblets.
Tips
usage
杂 here is 'miscellaneous [innards]' - the same morpheme appears in 猪杂 (pork offal), 牛杂 (beef offal), 下水 (general offal, colloquial). 鸡杂 on a menu typically means heart + gizzard + liver together.