Since we are setting "appearance: none" on our <select> elements, the
drop down arrow from the browser is hidden. This arrow doesn't fit in
visually though. This commit adds a new arrow from a simple data url
SVG. Its a dark triangle "pointing" downwards.
Note that we need to set the background to both the gradient and the
image here. Both use the "background-image" property for the graphic,
but since they are positioned differently we must use the general
"background" shorthand.
fc5bb6dab6