Cleanup cfwl_* files.

xfa/fwl/core/cfwl_edit.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_edit.h"
 
 #include <memory>
 #include <vector>
 
 #include "third_party/base/ptr_util.h"
 
 namespace {
 
 IFWL_Edit* ToEdit(IFWL_Widget* widget) {
   return static_cast<IFWL_Edit*>(widget);
 }
 
+const IFWL_Edit* ToEdit(const IFWL_Widget* widget) {
+  return static_cast<const IFWL_Edit*>(widget);
+}
+
 }  // namespace
 
 CFWL_Edit::CFWL_Edit(const IFWL_App* app) : CFWL_Widget(app) {}
 
 CFWL_Edit::~CFWL_Edit() {}
 
 void CFWL_Edit::Initialize() {
   ASSERT(!m_pIface);
 
   m_pIface = pdfium::MakeUnique<IFWL_Edit>(
       m_pApp, pdfium::MakeUnique<CFWL_WidgetProperties>(), nullptr);
 
   CFWL_Widget::Initialize();
 }
 
 void CFWL_Edit::SetText(const CFX_WideString& wsText) {
   if (GetWidget())
     ToEdit(GetWidget())->SetText(wsText);
 }
 
 void CFWL_Edit::GetText(CFX_WideString& wsText,
                         int32_t nStart,
-                        int32_t nCount) {
+                        int32_t nCount) const {
   if (GetWidget())
     ToEdit(GetWidget())->GetText(wsText, nStart, nCount);
 }
 
-int32_t CFWL_Edit::CountSelRanges() {
+int32_t CFWL_Edit::CountSelRanges() const {
   return GetWidget() ? ToEdit(GetWidget())->CountSelRanges() : 0;
 }
 
-int32_t CFWL_Edit::GetSelRange(int32_t nIndex, int32_t& nStart) {
+int32_t CFWL_Edit::GetSelRange(int32_t nIndex, int32_t& nStart) const {
   return GetWidget() ? ToEdit(GetWidget())->GetSelRange(nIndex, nStart) : 0;
 }
 
-int32_t CFWL_Edit::GetLimit() {
+int32_t CFWL_Edit::GetLimit() const {
   return GetWidget() ? ToEdit(GetWidget())->GetLimit() : -1;
 }
 
 void CFWL_Edit::SetLimit(int32_t nLimit) {
   if (GetWidget())
     ToEdit(GetWidget())->SetLimit(nLimit);
 }
 
 void CFWL_Edit::SetAliasChar(FX_WCHAR wAlias) {
   if (GetWidget())
     ToEdit(GetWidget())->SetAliasChar(wAlias);
 }
 
 void CFWL_Edit::SetScrollOffset(FX_FLOAT fScrollOffset) {
   if (GetWidget())
     ToEdit(GetWidget())->SetScrollOffset(fScrollOffset);
 }