Who gave the prophecy that if Zeus mated with Metis, their child would overthrow him?

An Oracle of Gaea(Zeus' grandmother) predicted this. She said the second child of Zeus and Metis(which would be a male) would be powerful enough to overthrow him and his reign, continuing the curse that runs down their bloodline(Ouranos overthrown by his male son Kronos, Kronos overthrown by his male son Zeus...). She swallowed Metis(when she said she was pregnant) due to this. Zeus had a mive headache afterwards. He then asks the help of Hephaestus to crack his head open. Out of his head, came Zeus and Metis "child", Athena, in a full set of war clothes. However, she vows never to turn on his father. This ends the family curse which surrounds Zeus' bloodline.