#Ruby, 61 bytes

If the spec were for the dots to scroll left instead of right, it would save 1 byte because rotate! with no arguments shifts the array once to the left.

s=[?.]*4+[' ']*6
loop{print ?[,*s,"]\r";s.rotate!9;sleep 0.1}

Ruby, 61 bytes

If the spec were for the dots to scroll left instead of right, it would save 1 byte because rotate! with no arguments shifts the array once to the left.

s=[?.]*4+[' ']*6
loop{print ?[,*s,"]\r";s.rotate!9;sleep 0.1}