Convert some flexbox tests to testharness.js

third_party/WebKit/LayoutTests/css3/flexbox/resources/box-orient-button.js

-description("Check if box-orient is working in <button>. See https://bugs.webkit.org/show_bug.cgi?id=25406");
 
 function setFlexDirection(element, flexDirection) {
     element.style.webkitFlexDirection = flexDirection;
     element.style.flexDirection = flexDirection;
 }
 
 function gebi(id) {
     return document.getElementById(id);
 }
 
 setFlexDirection(gebi("toVertical"), "column");
 setFlexDirection(gebi("toHorizontal"), "row");
 
 var referenceHorizontalHeight = gebi("reference_horizontal").clientHeight;
 var referenceVerticalHeight = gebi("reference_vertical").clientHeight;
-shouldBe("gebi('default').clientHeight", "referenceHorizontalHeight");
-shouldBe("gebi('horizontal').clientHeight", "referenceHorizontalHeight");
-shouldBe("gebi('vertical').clientHeight", "referenceVerticalHeight");
-shouldBe("gebi('toHorizontal').clientHeight", "referenceHorizontalHeight");
-shouldBe("gebi('toVertical').clientHeight", "referenceVerticalHeight");
-
-// If we are in DRT, we don't need meaningless messages.
-if (window.testRunner)
-    document.getElementById("main").innerHTML = "";
+test(function() { assert_equals(gebi('default').clientHeight, referenceHorizontalHeight); }, "default height");
+test(function() { assert_equals(gebi('horizontal').clientHeight, referenceHorizontalHeight); }, "horizontal height");
+test(function() { assert_equals(gebi('vertical').clientHeight, referenceVerticalHeight); }, "vertical height");
+test(function() { assert_equals(gebi('toHorizontal').clientHeight, referenceHorizontalHeight); }, "toHorizontal height");
+test(function() { assert_equals(gebi('toVertical').clientHeight, referenceVerticalHeight); }, "toVertical height");