1 A <video> should not have a layer until playback begins.
2 This test can not be run manually, it requires testRunner.layerTreeAsText.
4 Case: No src, no poster
10 "contentsOpaque": true,
17 Case: Displaying poster
23 "contentsOpaque": true,
30 Case: Displaying movie
36 "contentsOpaque": true,
44 "shouldFlattenTransform": false,