Merge delegates into IFWL_* classes.

xfa/fwl/core/ifwl_formproxy.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_FORMPROXY_H_
 #define XFA_FWL_CORE_IFWL_FORMPROXY_H_
 
 #include "xfa/fwl/core/ifwl_form.h"
 
 class CFWL_WidgetImpProperties;
-class CFWL_FormProxyImpDelegate;
 
 class IFWL_FormProxy : public IFWL_Form {
  public:
   IFWL_FormProxy(const IFWL_App* app,
                  const CFWL_WidgetImpProperties& properties,
                  IFWL_Widget* pOuter);
   ~IFWL_FormProxy() override;
 
   // IFWL_Widget
   FWL_Type GetClassID() const override;
   FX_BOOL IsInstance(const CFX_WideStringC& wsClass) const override;
   FWL_Error Update() override;
   FWL_Error DrawWidget(CFX_Graphics* pGraphics,
                        const CFX_Matrix* pMatrix = nullptr) override;
+  void OnProcessMessage(CFWL_Message* pMessage) override;
 
  protected:
   friend class CFWL_FormProxyImpDelegate;
 };
 
-class CFWL_FormProxyImpDelegate : public CFWL_WidgetImpDelegate {
- public:
-  CFWL_FormProxyImpDelegate(IFWL_FormProxy* pOwner);
-  void OnProcessMessage(CFWL_Message* pMessage) override;
-
- protected:
-  IFWL_FormProxy* m_pOwner;
-};
-
 #endif  // XFA_FWL_CORE_IFWL_FORMPROXY_H_