Move serializer related files in core/editing/ related files into core/editing/serializers/

Source/core/editing/serializers/StyledMarkupSerializerTest.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/StyledMarkupSerializer.h"
+#include "core/editing/serializers/StyledMarkupSerializer.h"
 
 #include "core/dom/Text.h"
 #include "core/editing/EditingTestBase.h"
 
 namespace blink {
 
 // This is smoke test of |StyledMarkupSerializer|. Full testing will be done
 // in layout tests.
 class StyledMarkupSerializerTest : public EditingTestBase {
 protected:
@@ skipping 207 matching lines @@
     RefPtrWillBeRawPtr<Element> span2 = document().getElementById("span2");
     Position startDOM = Position::firstPositionInNode(span1.get());
     Position endDOM = Position::lastPositionInNode(span2.get());
     EXPECT_EQ("", serializePart<EditingStrategy>(startDOM, endDOM));
     PositionInComposedTree startICT = PositionInComposedTree::firstPositionInNode(span1.get());
     PositionInComposedTree endICT = PositionInComposedTree::lastPositionInNode(span2.get());
     EXPECT_EQ("", serializePart<EditingInComposedTreeStrategy>(startICT, endICT));
 }
 
 } // namespace blink