samples/bluetooth/hci_usb/src/Makefile - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 ccflags-y += -I${ZEPHYR_BASE}/usb/include -I${ZEPHYR_BASE}/include/drivers/usb -I${ZEPHYR_BASE}/include/usb/

 obj-y += main.o
	ccflags-y += -I${ZEPHYR_BASE}/usb/include -I${ZEPHYR_BASE}/include/drivers/usb -I${ZEPHYR_BASE}/include/usb/

	obj-y += main.o