Summarize the following:
You'll need two golden apples—one for each horse—which means you need the following resources:   2 apples — Used as the base for the golden apples.  16 gold bars — You can create gold bars by smelting gold ore in a furnace.  1 Crafting Table — Used to make the golden apples. If you don't yet have a Crafting Table, make one before proceeding. This process will vary slightly depending on your platform:   PC — Open your Crafting Table, click the stack of gold bars, right-click twice each box in the Crafting Table except for the center one, place both apples in the center box, and move the two gold apples into your inventory.  Mobile — Open your Crafting Table, tap the magnifying glass icon on the left side of the screen, and tap twice the gold apple icon.  Consoles — Open your Crafting Table, select the magnifying glass tab, and select twice the gold apple icon. You'll want to make sure that neither of the horses escape when entering the enclosure. Feeding a golden apple to a horse that you've accidentally attacked will result in the horse being fed rather than being primed for mating. If your horses aren't both at full health, feed each of them red apples until they stop eating. In your equip bar at the bottom of the screen, make sure you have the golden apples selected. Right-click or left-trigger each of the horses with the golden apples equipped. Doing so will prompt red hearts to appear over each horse's head, signifying that they're ready to breed. On Minecraft PE, you'll face each horse and tap Feed at the bottom of the screen. After a few seconds, you should see a small horse appear in the enclosure. This is the foal that the two tamed horses created.

Summary:
Gather the resources for golden apples. Craft two golden apples. Enter your horses' enclosure. Make sure that both horses are at full health. Equip the golden apples. Select each horse. Wait for a foal to appear.