The text test expectation seems to be incorrectly rebaselined at some point. According to the pixel test, the second video should be a bit shrinked, but in trunk it is not, currently.
The test is flaky right now, sometimes it time outs since r173689. Updating expectations on webkit.org/b/143467.
There are no references to this bug in any TestExpectations. It's probable this bug was solved at some point but it wasn't marked as closed. I'm closing this bug now. If you think this bug report is still valid, please reopen it and add an entry to TestExpectations.