To accomplish this, I made the following changes:
1) Material is now in charge of drawing the material shadows.
2) In order to mix in the style for the shadow, Element now takes a list of
Styles instead of a single style.
3) Update all clients of Element#style to understand that we now have a list.
4) Update components that drawer shadows to have Material do that work instead.
a) One exception: FloatingActionButton draws its own shadow because of its
crazy clip requirements. We'll probably want to find a better way for
FloatingActionButton to clip in the future.
I've also added a widgets-fn example to demo the fn material widgets.
This CL introduces a bug into Drawer whereby you can get ink splashes
everywhere in the drawer. In the future, we'll need to separate out the
different material aspects to get non-splashable materials.
R=rafaelw@chromium.org
Review URL: https://codereview.chromium.org/1003553002
