6bb7c0ae9c
This animation expands/collapses an arc that's 3/4ths of a circle. The next iteration begins where the previous appeared to finish. This happens while the whole thing rotates, such that the starting point of each expansion moves in a star-wise pattern around the circle. See: https://www.google.com/design/spec/components/progress-activity.html (note: the video here demonstrating this animation is actually slightly incorrect... we'll hopefully update it soon)