Make rendersInDifferentPosition() to work with AfterAnchor and AfterChildren positions properly

Source/core/dom/PositionTest.cpp

Index: Source/core/dom/PositionTest.cpp
diff --git a/Source/core/dom/PositionTest.cpp b/Source/core/dom/PositionTest.cpp
index b32237081058e0c31104c0624549c5f4179aa804..2462daf161001835a0281ca64e7d1314c636b5c9 100644
--- a/Source/core/dom/PositionTest.cpp
+++ b/Source/core/dom/PositionTest.cpp
@@ -102,6 +102,17 @@ TEST_F(PositionTest, NodeAsRangeLastNodeShadow)
     EXPECT_EQ(t1, PositionInComposedTree::afterNode(host).nodeAsRangeLastNode());
 }
 
+TEST_F(PositionTest, rendersInDifferentPositionAfterAnchor)
+{
+    const char* bodyContent = "<p id='sample'>00</p>";
+    setBodyContent(bodyContent);
+    updateLayoutAndStyleForPainting();
+    RefPtrWillBeRawPtr<Element> sample = document().getElementById("sample");
+
+    EXPECT_FALSE(Position::afterNode(sample.get()).rendersInDifferentPosition(Position(sample.get(), 1)));
+    EXPECT_FALSE(Position::lastPositionInNode(sample.get()).rendersInDifferentPosition(Position(sample.get(), 1)));
+}
+
 TEST_F(PositionTest, ToPositionInComposedTreeWithActiveInsertionPoint)
 {
     const char* bodyContent = "<p id='host'>00<b id='one'>11</b>22</p>";