It's very easy...
 
G           F                      C        D
Pink, It's my new obsession...
 
The whole music is like this, but changes this part
 
          G            C            D                G          C       
D                     G  
And I think everything is goin' to be all right no matter what we do tonight...
 
And starts again...
 
Now, the tabs...
 
G | -----------------------------
D | -----------------------------
A | ---------3--5---------------
E | --3--1----------------------
 
chorus:
 
G | ---------------------------------------------------------------|
D | ---------------------------------------------------------------|
A | ------------3---5-----------3---5----------------3--5------|
E | -------3-----------------3------------------3--1------------| 
 
That's it. Easy, huh?