Cleanup env variable names

fpdfsdk/fpdfxfa/cpdfxfa_document.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 "fpdfsdk/fpdfxfa/cpdfxfa_document.h"
 
 #include "core/fpdfapi/parser/cpdf_document.h"
 #include "fpdfsdk/cpdfsdk_formfillenvironment.h"
@@ skipping 26 matching lines @@
       m_pApp(pProvider),
       m_nLoadStatus(FXFA_LOADSTATUS_PRELOAD),
       m_nPageCount(0),
       m_DocEnv(this) {}
 
 CPDFXFA_Document::~CPDFXFA_Document() {
   m_nLoadStatus = FXFA_LOADSTATUS_CLOSING;
 
   if (m_pFormFillEnv) {
     m_pFormFillEnv->ClearAllFocusedAnnots();
-    // Once we're deleted the SDKDocument will point at a bad underlying
+    // Once we're deleted the FormFillEnvironment will point at a bad underlying
     // doc so we need to reset it ...
     m_pFormFillEnv->ResetXFADocument();
     m_pFormFillEnv = nullptr;
   }
 
   if (m_pXFADoc) {
     CXFA_FFApp* pApp = m_pApp->GetXFAApp();
     if (pApp) {
       CXFA_FFDocHandler* pDocHandler = pApp->GetDocHandler();
       if (pDocHandler)
@@ skipping 138 matching lines @@
 }
 
 void CPDFXFA_Document::RemovePage(CPDFXFA_Page* page) {
   m_XFAPageList.SetAt(page->GetPageIndex(), nullptr);
 }
 
 void CPDFXFA_Document::ClearChangeMark() {
   if (m_pFormFillEnv)
     m_pFormFillEnv->ClearChangeMark();
 }