Test DOMMatrixReadOnly methods do not mutate the object


PASS test translate() doesn't mutate 
PASS test scale() doesn't mutate 
PASS test scale3d() doesn't mutate 
PASS test rotate() doesn't mutate 
PASS test rotateFromVector() doesn't mutate 
PASS test rotateAxisAngle() doesn't mutate 
PASS test skewX() doesn't mutate 
PASS test skewY() doesn't mutate 
PASS test multiply() doesn't mutate 
PASS test flipX() doesn't mutate 
PASS test flipY() doesn't mutate 
PASS test inverse() doesn't mutate