Cleanup env variable names

fpdfsdk/cfx_systemhandler.h

 // Copyright 2016 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 FPDFSDK_CFX_SYSTEMHANDLER_H_
 #define FPDFSDK_CFX_SYSTEMHANDLER_H_
 
 #include "core/fxcrt/fx_coordinates.h"
@@ skipping 31 matching lines @@
 #define FXCT_HAND 5
 
 class CFFL_FormFiller;
 class CPDF_Document;
 class CPDF_Font;
 class CPDFSDK_FormFillEnvironment;
 class CPDFSDK_Widget;
 
 class CFX_SystemHandler {
  public:
-  explicit CFX_SystemHandler(CPDFSDK_FormFillEnvironment* pEnv)
-      : m_pEnv(pEnv) {}
+  explicit CFX_SystemHandler(CPDFSDK_FormFillEnvironment* pFormFillEnv)
+      : m_pFormFillEnv(pFormFillEnv) {}
   ~CFX_SystemHandler() {}
 
   void InvalidateRect(CPDFSDK_Widget* widget, FX_RECT rect);
   void OutputSelectedRect(CFFL_FormFiller* pFormFiller, CFX_FloatRect& rect);
   bool IsSelectionImplemented() const;
 
   void SetCursor(int32_t nCursorType);
 
   bool FindNativeTrueTypeFont(CFX_ByteString sFontFaceName);
   CPDF_Font* AddNativeTrueTypeFontToPDF(CPDF_Document* pDoc,
                                         CFX_ByteString sFontFaceName,
                                         uint8_t nCharset);
 
   int32_t SetTimer(int32_t uElapse, TimerCallback lpTimerFunc);
   void KillTimer(int32_t nID);
 
   bool IsSHIFTKeyDown(uint32_t nFlag) const;
   bool IsCTRLKeyDown(uint32_t nFlag) const;
   bool IsALTKeyDown(uint32_t nFlag) const;
 
  private:
-  CPDFSDK_FormFillEnvironment* const m_pEnv;
+  CPDFSDK_FormFillEnvironment* const m_pFormFillEnv;
 };
 
 #endif  // FPDFSDK_CFX_SYSTEMHANDLER_H_