Make contenteditable="false" element as atomic node for selection motion

LayoutTests/editing/selection/4889598.html

Index: LayoutTests/editing/selection/4889598.html
diff --git a/LayoutTests/editing/selection/4889598.html b/LayoutTests/editing/selection/4889598.html
deleted file mode 100644
index 435e8da9a294ccee2b6c2e92bdcd000ca61ad45f..0000000000000000000000000000000000000000
--- a/LayoutTests/editing/selection/4889598.html
+++ /dev/null
@@ -1,22 +0,0 @@
-<p>This tests for a bug moving down by a line from a line just above a ToDo, and moving up by a line from just below a ToDo.</p>
-<div id="div" contenteditable="true">
-<div id="above">Click anywhere in this line and move down.</div>
-<table border="1" contenteditable="false"><tr><td>The caret <span style="color: blue;" contenteditable="true">should</span> always go into the editable region.</td></tr></table>
-<div id="below">Click anywhere in this line and move up.</div>
-</div>
-
-<script>
-if (window.testRunner)
-    window.testRunner.dumpEditingCallbacks();
-var selection = window.getSelection();
-var above = document.getElementById("above").firstChild;
-selection.setPosition(above, 0);
-selection.modify("move", "forward", "line");
-selection.setPosition(above, above.length);
-selection.modify("move", "forward", "line");
-var below = document.getElementById("below").firstChild;
-selection.setPosition(below, 0);
-selection.modify("move", "backward", "line");
-selection.setPosition(below, below.length);
-selection.modify("move", "backward", "line");
-</script>