Walk bass down on D string through the 7th fret barred Bm sequence for the verses ;
9-8-7-6 on D string while maintaining barre on bottom 3 strings(see chords below). 
Standard tuning.

Bm                   BmM7.      Bm7.        Bm6/G#
If you were the ocean and I was the sun
Bm                          BmM7.      Bm7.    Bm6/G#
If the day made me heavy and gravity won
Bm            .BmM7.  Bm7.             Bm6/G#
If I was the red and you were the blue
G7.             F#7.       Bm
I could just fade into you!

Bm                 BmM7.        Bm7.      Bm6/G#
If you were a window and I was the rain
Bm.                  BmM7.  Bm7.           Bm6/G#
I'd pour myself out and wash off the pain
Bm              BmM7.         Bm7.                  Bm6/G#
I'd fall like a tear so your light could shine through
G7.              F#7.         Bm
Then I'd just fade into you!

Chorus:
Bm.               A                  G
In your heart in your head in your
                           F#7
arms in your bed under your skin
Bm.                A.                  G
Til' there's no way to know where
                     F#7
you end and where I begin
( Tab from: http://www.guitaretab.com/s/sam-palladio-and-clare-bowen/336113.html )
Bm          BmM7.         Bm7.          Bm6/G#
If I was a shadow and you were a street
Bm                      BmM7.       Bm7.                Bm6/G#
The cobblestone midnight is where we first meet
Bm                              BmM7.  Bm7.               Bm6/G#
Til' the lights flickered out, we dance with the moon
G7.               F#7.       Bm
Then I'd just fade into you

Chorus 2:
Bm.               A                  G
In your heart in your head in your
                           F#7
arms in your bed under your skin
Bm.               A                  G
Til' there's no way to know where
                     F#7
you end and where I begin
Bm.               A                  G
I wanna melt in I wanna soak through
                              F#7
I only wanna move when you move
Bm.               A                  G
I wanna breathe out when you
                                     F#7
breathe in then I wanna fade into you

Bm               BmM7.     Bm7.             Bm6/G#
If I was just ashes and you were the ground
Bm.                   BmM7  Bm7.          Bm6/G#
And under your willow they laid me down
Bm                 BmM7.     Bm7.              Bm6/G#
There'll be no trace that one was once two
G7.      F#7.      Bm
After I fade into you

(Ooooh….)
G7.                 F#7.        Bm
Then I'd just fade into you (4x)