Split xfa_object_imp into individual class files.

xfa/fxfa/parser/cxfa_thisproxy.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/xfa_object.h"
+
+CXFA_ThisProxy::CXFA_ThisProxy(CXFA_Node* pThisNode, CXFA_Node* pScriptNode)
+    : CXFA_Object(pThisNode->GetDocument(),
+                  XFA_ObjectType::VariablesThis,
+                  XFA_Element::Unknown,
+                  CFX_WideStringC()),
+      m_pThisNode(nullptr),
+      m_pScriptNode(nullptr) {
+  m_pThisNode = pThisNode;
+  m_pScriptNode = pScriptNode;
+}
+
+CXFA_ThisProxy::~CXFA_ThisProxy() {}
+
+CXFA_Node* CXFA_ThisProxy::GetThisNode() const {
+  return m_pThisNode;
+}
+
+CXFA_Node* CXFA_ThisProxy::GetScriptNode() const {
+  return m_pScriptNode;
+}