Introduce composed tree version of directionOfEnclosingBlock()

Source/core/editing/EditingUtilitiesTest.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/editing/EditingUtilities.h"
 
 #include "core/editing/EditingTestBase.h"
 
 namespace blink {
 
 class EditingUtilitiesTest : public EditingTestBase {
 };
 
+TEST_F(EditingUtilitiesTest, directionOfEnclosingBlock)
+{
+    const char* bodyContent = "<p id='host'><b id='one'></b><b id='two'>22</b></p>";
+    const char* shadowContent = "<content select=#two></content><p dir=rtl><content select=#one></content><p>";
+    setBodyContent(bodyContent);
+    setShadowContent(shadowContent);
+    updateLayoutAndStyleForPainting();
+    Node* one = document().getElementById("one");
+
+    EXPECT_EQ(LTR, directionOfEnclosingBlock(Position(one, 0)));
+    EXPECT_EQ(RTL, directionOfEnclosingBlock(PositionInComposedTree(one, 0)));
+}
+
 TEST_F(EditingUtilitiesTest, firstEditablePositionAfterPositionInRoot)
 {
     const char* bodyContent = "<p id='host' contenteditable><b id='one'></b><b id='two'>22</b></p>";
     const char* shadowContent = "<content select=#two></content><content select=#one></content><b id='three'>333</b>";
     setBodyContent(bodyContent);
     RefPtrWillBeRawPtr<ShadowRoot> shadowRoot = setShadowContent(shadowContent);
     updateLayoutAndStyleForPainting();
     Node* host = document().getElementById("host");
     Node* one = document().getElementById("one");
     Node* three = shadowRoot->getElementById("three");
@@ skipping 58 matching lines @@
     updateLayoutAndStyleForPainting();
     Node* one = document().getElementById("one");
     Node* two = document().getElementById("two");
     Node* three = document().getElementById("three");
 
     EXPECT_EQ(Position(two->firstChild(), 1), nextVisuallyDistinctCandidate(Position(one, 1)));
     EXPECT_EQ(PositionInComposedTree(three->firstChild(), 1), nextVisuallyDistinctCandidate(PositionInComposedTree(one, 1)));
 }
 
 } // namespace blink