I created this tab by looking at several others and listening to the song. I think 
it's completely accurate, but let me know if you have suggestions. 

C                         [ch]Fmaj7/C[/ch]        
  What if we stop having a ball?
C                                  [ch]Fmaj7/C[/ch]
  What if the paint chips from the wall?
Am                                   Random D7
  What if there's always cups in the sink?
D7                        F              C
  What if I'm not what you think, think I am?

Verse:
What if I fall further than you?
What if you dream of somebody new?
What if I never let you win, chase you with a rolling pin?
Well what if I do?

Chorus:
       F    G7      C
'Cause I am giving up on making passes and
F    G7      C           Random C
I am giving up on half empty glassess and
F    G7      Am           D7
I am giving up on greener grasses.
F      G       C
I am giving up.

Verse:
What if our baby comes home after nine?
What it your eyes close before mine?
What if you lose yourself sometimes? Then I'll be the one to find you
Safe in my heart.


Chorus:
I am giving up on making passes and
I am giving up on half empty glassess and
I am giving up on greener grasses.
I am giving up.

Bridge/outro:
F    G7      C RC
I am giving up.
F    G      C  RC
I am giving up.
F    G      Am         D7
I am giving up on greener grasses.
F    G      Am      D7
I am giving up for you.
F    G      Am      D7
I am giving up for you.
F    G      C
I am giving up.