This tests the data attribute of the TextEvent
interface.
To perform the test, the user must input some text. This can be
(as mentioned by DOM Level 3 Events specification) from a variety of
sources, such characters directly from a keyboard, text pasted from
the clipboard, input from an IME or input from a speech recognizer.
Once the text has been input, the black rectangle should turn blue to
indicate that the test has been passed. In addition, the
text element below the rectangle will show the text that was
input. If the rectangle becomes red, the test failed because the
data attribute had an invalid value.
