selection: Update addRange-nn.html for 20170227 draft.

third_party/WebKit/LayoutTests/external/wpt/selection/common.js

 "use strict";
 // TODO: iframes, contenteditable/designMode
 
 // Everything is done in functions in this test harness, so we have to declare
 // all the variables before use to make sure they can be reused.
 var selection;
 var testDiv, paras, detachedDiv, detachedPara1, detachedPara2,
     foreignDoc, foreignPara1, foreignPara2, xmlDoc, xmlElement,
     detachedXmlElement, detachedTextNode, foreignTextNode,
     detachedForeignTextNode, xmlTextNode, detachedXmlTextNode,
@@ skipping 946 matching lines @@
         selection.collapse(endpoints[2], endpoints[3]);
         selection.extend(endpoints[0], endpoints[1]);
     }
 }
 
 /**
  * Verify that the specified func doesn't change the selection.
  * This function should be used in testharness tests.
  */
 function assertSelectionNoChange(func) {
-    var originalCount = getSelection().rangeCount;
+    var originalCount = selection.rangeCount;
     var originalRange = originalCount == 0 ? null : selection.getRangeAt(0);
+    var originalAnchorNode = selection.anchorNode;
+    var originalAnchorOffset = selection.anchorOffset;
+    var originalFocusNode = selection.focusNode;
+    var originalFocusOffset = selection.focusOffset;
 
     func();
 
     assert_equals(selection.rangeCount, originalCount,
         "The operation should not add Range");
+    assert_equals(selection.anchorNode, originalAnchorNode,
+        "The operation should not update anchorNode");
+    assert_equals(selection.anchorOffset, originalAnchorOffset,
+        "The operation should not update anchorOffset");
+    assert_equals(selection.focusNode, originalFocusNode,
+        "The operation should not update focusNode");
+    assert_equals(selection.focusOffset, originalFocusOffset,
+        "The operation should not update focusOffset");
     if (originalCount < 1)
         return;
     assert_equals(selection.getRangeAt(0), originalRange,
          "The operation should not replace a registered Range");
 }
 
 /**
  * Check if the specified node can be selectable with window.getSelection()
  * methods.
  */
 function isSelectableNode(node) {
     if (!node)
         return false;
     if (node.nodeType == Node.DOCUMENT_TYPE_NODE)
         return false;
     return document.contains(node);
 }