[Editing][CodeHealth] Use w3c testharness in editing/seletion/move-by-*

third_party/WebKit/LayoutTests/editing/selection/move-by-character-brute-force.html

-<meta charset="UTF-8">
-<script src="../../resources/js-test.js"></script>
-<div id="test"></div>
-<script>
-description("This test checks that we have simple caret motion up to a certain limit");
-
-function hasSimpleCaretMovement(charCode) {
-    var testString = "aaaaa" + String.fromCharCode(charCode) + "bbbb";
-    element.textContent = testString;
-    var selection = window.getSelection();
-    selection.collapse(element, 0);
-    for (var i = 0; i < testString.length; ++i) {
-        selection.modify("move", "forward", "character");
-        if (selection.baseOffset != i + 1)
-            return false;
-    }
-    return true;
-}
-
-function toHex(i) {
-    var hex = i.toString(16);
-    while (hex.length < 4)
-        hex = "0" + hex;
-    return hex;
-}
-
-var element = document.getElementById("test");
-
-debug("Positive control:");
-shouldBeTrue("hasSimpleCaretMovement(0x0041)");
-debug("");
-
-debug("Negative control:");
-shouldBeFalse("hasSimpleCaretMovement(0x0300)");
-debug("");
-
-debug("Brute force:");
-for (var i = 1; i < 1024; ++i) {
-    if (i >= 0x0300 && i <= 0x036F)
-        shouldBeFalse("hasSimpleCaretMovement(i) // i = U+" + toHex(i));
-    else
-        shouldBeTrue("hasSimpleCaretMovement(i) // i = U+" + toHex(i));
-}
-
-element.textContent = "";
-</script>