[Editing][CodeHealth] Convert editing/selection to utilize w3c test harness part 1.

third_party/WebKit/LayoutTests/editing/selection/4947387.html

-<p>This tests moveTo{Beginning, End}OfLineAndModifySelection.  It should operate on line boundaries and not paragraph boundaries.  To run it manually, click inside the first line of the editable region below and do Command+Shift+Left/Right Arrow, the selection should extend to the start/end of the line, not the start/end of the paragraph.  Also, moveTo{Beginning, End}OfParagraphAndModifySelection should work.</p>
-<div id="div" contenteditable="true" style="width: 200px;">The quick brown fox jumped over the lazy brown dog.</div>
-
-<script>
-
-if (window.testRunner) {
-
-    window.testRunner.dumpEditingCallbacks();
-    
-    var div = document.getElementById("div");
-    var text = div.firstChild;
-    var sel = window.getSelection();
-    
-    sel.collapse(text, text.length);
-    testRunner.execCommand("MoveToBeginningOfLineAndModifySelection");
-    
-    sel.collapse(text, 0);
-    testRunner.execCommand("MoveToEndOfLineAndModifySelection");
-
-    sel.collapse(text, text.length);
-    testRunner.execCommand("MoveToBeginningOfParagraphAndModifySelection");
-    
-    sel.collapse(text, 0);
-    testRunner.execCommand("MoveToEndOfParagraphAndModifySelection");
-}
-</script>