Rename IFWL_App to CFWL_App

xfa/fwl/core/cfwl_pushbutton.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/fwl/core/cfwl_pushbutton.h"
 
 #include <memory>
 
 #include "third_party/base/ptr_util.h"
 
-CFWL_PushButton::CFWL_PushButton(const IFWL_App* app) : CFWL_Widget(app) {}
+CFWL_PushButton::CFWL_PushButton(const CFWL_App* app) : CFWL_Widget(app) {}
 
 CFWL_PushButton::~CFWL_PushButton() {}
 
 void CFWL_PushButton::Initialize() {
   ASSERT(!m_pIface);
 
   m_pIface = pdfium::MakeUnique<IFWL_PushButton>(
       m_pApp, pdfium::MakeUnique<CFWL_WidgetProperties>(this));
 
   CFWL_Widget::Initialize();
 }