1 Series of tests to ensure correct behavior of canvas.clearRect().
3 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
6 Test canvas.clearRect() with height = width = 0.
10 Test canvas.clearRect() with height = 0, width = 1.
11 PASS imgdata[0] is 255
14 Test canvas.clearRect() with height = 1, width = 0.
15 PASS imgdata[0] is 255
18 PASS successfullyParsed is true