Currently when the queue is populated with items that have cover art and then those items are removed from the queue the blurred background remains identical to the last item removed. Instead it should be reset to the default cover art.
To reproduce:
1. From the Music tab flick upward to show the Albums on the device
2. Select an album with cover art
3. Expand one of the items/songs
4. Select "Add to queue"
5. Click the "Close" button
6. Note that the blurred background in the app has changed
7. Flick up from the bottom of the app to expose the Music toolbar
8. Click on the title of the track to go to the Now Playing page
9 Swipe the track to the left and click "Clear" to remove it from the queue
10. Note that the background still matches what was previously in the queue.
Expected results: Step #9 causes the app's background to go back to the default cover art that is displayed when the app starts.
Fix committed into lp:music-app at revision 424, scheduled for release in music-app, milestone 1.0