Replace calls to deprecated CFX_{Wide,Byte}String::Empty()

xfa/fxfa/parser/xfa_document_serialize.cpp

 // Copyright 2014 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_document_serialize.h"
 
 #include "xfa/fde/xml/fde_xml_imp.h"
 #include "xfa/fgas/crt/fgas_codepage.h"
@@ skipping 171 matching lines @@
   CXFA_WidgetData* pWidgetData = pGrandParentNode->GetWidgetData();
   XFA_ELEMENT eUIType = pWidgetData->GetUIType();
   if (eUIType == XFA_ELEMENT_PasswordEdit) {
     return FALSE;
   }
   return TRUE;
 }
 static void XFA_DataExporter_RecognizeXFAVersionNumber(
     CXFA_Node* pTemplateRoot,
     CFX_WideString& wsVersionNumber) {
-  wsVersionNumber.Empty();
+  wsVersionNumber.clear();
   if (!pTemplateRoot) {
     return;
   }
   CFX_WideString wsTemplateNS;
   if (!pTemplateRoot->TryNamespace(wsTemplateNS)) {
     return;
   }
   XFA_VERSION eVersion =
       pTemplateRoot->GetDocument()->RecognizeXFAVersionNumber(wsTemplateNS);
   if (eVersion == XFA_VERSION_UNKNOWN) {
@@ skipping 126 matching lines @@
       CXFA_Node* pChildNode = pNode->GetNodeItem(XFA_NODEITEM_FirstChild);
       while (pChildNode) {
         XFA_DataExporter_RegenerateFormFile_Changed(pChildNode, newBuf,
                                                     bSaveXML);
         wsChildren += newBuf.GetWideString();
         newBuf.Clear();
         pChildNode = pChildNode->GetNodeItem(XFA_NODEITEM_NextSibling);
       }
       if (!bSaveXML && !wsChildren.IsEmpty() &&
           pNode->GetClassID() == XFA_ELEMENT_Items) {
-        wsChildren.Empty();
+        wsChildren.clear();
         bSaveXML = TRUE;
         CXFA_Node* pChildNode = pNode->GetNodeItem(XFA_NODEITEM_FirstChild);
         while (pChildNode) {
           XFA_DataExporter_RegenerateFormFile_Changed(pChildNode, newBuf,
                                                       bSaveXML);
           wsChildren += newBuf.GetWideString();
           newBuf.Clear();
           pChildNode = pChildNode->GetNodeItem(XFA_NODEITEM_NextSibling);
         }
       }
@@ skipping 225 matching lines @@
         pXMLElement->RemoveAttribute(L"xfa:dataNode");
       }
     } else {
       CFDE_XMLNode* pXMLNode = pDataNode->GetXMLMappingNode();
       FXSYS_assert(pXMLNode->GetType() == FDE_XMLNODE_Element);
       static_cast<CFDE_XMLElement*>(pXMLNode)
           ->SetString(FX_WSTRC(L"xfa:dataNode"), FX_WSTRC(L"dataGroup"));
     }
   }
 }