With the recent addition of pckbc_acpi, it seems only a small change is
needed for my chromebook keyboard to work. This is running on an acer
CP514-3HH-R6VK

diff /home/bmercer/src
path + /home/bmercer/src
commit - c7df606a226b2afe5e5ddf0eb9f8fa7a1638d0fe
blob - ab6368f0ece350b2d78d377b699002b7983d205c
file + sys/dev/acpi/pckbc_acpi.c
--- sys/dev/acpi/pckbc_acpi.c
+++ sys/dev/acpi/pckbc_acpi.c
@@ -130,6 +130,7 @@ pckbc_acpi_attach(struct device *parent, struct device
 }
 
 const char *pckbc_acpi_cids_kbd[] = {
+	"GOOG000A",	/* Chromebook built-in keyboard */
 	"PNP0303",	/* IBM Enhanced Keyboard (101/102-key, PS/2 Mouse) */
 	NULL
 };