[HighResolutionTime] Test Cases

I have finished reviewing the High Resolution Time test cases:
http://w3c-test.org/webperf/tests/submission/Google/HighResolutionTime/test_cross_frame_start.html
http://w3c-test.org/webperf/tests/submission/W3C/HighResolutionTime/monotonic-clock.html
http://w3c-test.org/webperf/tests/submission/W3C/HighResolutionTime/basic.html

The first two tests, test_cross_frame_start.html and monotonic-clock.html, look good as is. I recommend we move these tests to the approved folder.

For the last test, basic.html, I recommend a minor tweak. For the first test in this test case, we should change the typeof assert to be for "object" instead of the assert_equals(window.performance.toString(), "[object Performance]"); .  The rest of the tests in this test case look good. (I see that the third test had been changed from an assert_equals(window.performance.now.toString().indexOf("function"), 0, ...); to  assert_equals(typeof window.performance.now, "function", ...), which is the correct test).

All of the test cases are passing in IE10 and Firefox 15. There are some failures in Chrome 22, however, that might be attributed to the prefixed now() function. I'll let Tony comment.

Thanks,
Jatinder