I can confirm that the patrol chests have a chance to be what I call either common, rare, or legendary. Common - Glimmer, a chance at one or two green items/engrams, as well as a chance at a ship, and materials. Rare - More glimmer, one or two blue engrams, increased material gain, and ammo synths of some kind. Sometimes motes or strange coins as well. Legendary - Even more glimmer, blue engrams (sometimes purple), materials, ammo, and sometimes one or two ascendant materials. I can't confirm the legendary entirely, it could be a rare with epic drops, but I feel it deserves a category as it is very rare. I've only gotten two or three.