Although cacao trees flourish in the tropical climes of the Philippines, chocolate is not indigenous to the islands. In fact, like a few other Filipino foods, chocolate was introduced to the Philippines by Spain via Mexico (the cacao tree IS indigenous to parts of Central and South America).
In fact, according to many historical accounts, the ancient Mayans are credited with the invention of hot chocolate. Originally, the Mayans simply ground native cacao beans and spices into a paste, and then frothed the mixture into water and served this concoction hot. Soon, the Aztecs were introduced to cacao beans and made a similar chocolate brew of their own--though it was a cold drink that was served during religious ceremonies and human sacrifices (oh, those crazy Aztecs).
Then one day, some Spanish dude named Cortez arrived in Mexico and was peacefully received by Aztec emperor Montezuma. As the story goes, Montezuma presented Cortez with a frothy cup of chocolate out of simple good will. In return, Cortez wiped out the entire Aztec civilization (oh, those crazy Spaniards).
Finally, to make a long story a little bit less long, about a hundred (give or take) years later the Spanish took the cacao trees (as well as the Mexican custom of drinking chocolate) from their Mexican colony and introduced it to their Philippine colony. Thus, Filipinos started growing their own cacao trees, and then making and drinking their own form of hot chocolate known as Tsokolate.