Rename IFWL classes which do not have CFWL equivalents

xfa/fwl/core/cfwl_datetimeedit.h

 // 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
 
-#ifndef XFA_FWL_CORE_IFWL_DATETIMEEDIT_H_
-#define XFA_FWL_CORE_IFWL_DATETIMEEDIT_H_
+#ifndef XFA_FWL_CORE_CFWL_DATETIMEEDIT_H_
+#define XFA_FWL_CORE_CFWL_DATETIMEEDIT_H_
 
 #include <memory>
 
 #include "xfa/fwl/core/cfwl_widgetproperties.h"
 #include "xfa/fwl/core/fwl_error.h"
 #include "xfa/fwl/core/ifwl_edit.h"
 #include "xfa/fwl/core/ifwl_widget.h"
 
-class IFWL_DateTimeEdit : public IFWL_Edit {
+class CFWL_DateTimeEdit : public IFWL_Edit {
  public:
-  IFWL_DateTimeEdit(const CFWL_App* app,
+  CFWL_DateTimeEdit(const CFWL_App* app,
                     std::unique_ptr<CFWL_WidgetProperties> properties,
                     IFWL_Widget* pOuter);
 
   // IFWL_Edit.
   void OnProcessMessage(CFWL_Message* pMessage) override;
 
  private:
   void DisForm_OnProcessMessage(CFWL_Message* pMessage);
 };
 
-#endif  // XFA_FWL_CORE_IFWL_DATETIMEEDIT_H_
+#endif  // XFA_FWL_CORE_CFWL_DATETIMEEDIT_H_