Rename xfa_doclayout and xfa_document_layout_imp files.

xfa/fxfa/parser/cxfa_contentlayoutitem.cpp

+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "xfa/fxfa/parser/cxfa_contentlayoutitem.h"
+
+CXFA_ContentLayoutItem::CXFA_ContentLayoutItem(CXFA_Node* pNode)
+    : CXFA_LayoutItem(pNode, TRUE),
+      m_pPrev(nullptr),
+      m_pNext(nullptr),
+      m_dwStatus(0) {}
+
+CXFA_ContentLayoutItem::~CXFA_ContentLayoutItem() {
+  if (m_pFormNode->GetUserData(XFA_LAYOUTITEMKEY) == this)
+    m_pFormNode->SetUserData(XFA_LAYOUTITEMKEY, nullptr);
+}