Bug 979636 - Unit tests for video app -- showPlayer unit tests

One issue with the showPlayer unit tests is that the video player element considers the player to be seeking in setVideoUrl. That is, for all the showPlayer unit tests, dom.player.seeking is always true resulting in the tests needing to account for the asynchronous behavior of waiting for dom.player.onseeked to be called.

I don't know why the player thinks it is seeking during the unit tests. Ideally, the tests would be able to specify/configure the tests such that sometimes the player is seeking and sometimes not; this I have not been able to do.