Pretty simple bass. Just play these beats the entire song.
G|----------------------------------------------------------------|
D|----7-------7-------7-------7-------7-------7-------7-------7---|
A|----------------------------------------------------------------|
E|5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-|
G|----------------------------------------------------------------|
D|----7-------7-------7-------7-------7-------7-------7-------7---|
A|5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-5-5---5-|
E|----------------------------------------------------------------|
Enjoy!