from the radio 1 live lounge version,

sounds to me its different variations of these three chords all the way through.

e--------------------------------------|
b--------------------------------------|
g---7-7-7-7-7-7--15-15-15---12-12-12---|
d---7-7-7-7-7-7--15-15-15---12-12-12---|
a---5-5-5-5-5-5--13-13-13---10-10-10---|
e--------------------------------------|