Get rid of NULLs in fpdfsdk/

fpdfsdk/fpdfformfill.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 "public/fpdf_formfill.h"
 
 #include <memory>
 #include <vector>
@@ skipping 121 matching lines @@
   options.m_AddFlags = flags >> 8;
   options.m_pOCContext = new CPDF_OCContext(pPDFDoc, CPDF_OCContext::View);
 
   if (CPDFSDK_PageView* pPageView = pFXDoc->GetPageView(pPage))
     pPageView->PageView_OnDraw(pDevice.get(), &matrix, &options, clip);
 #endif  // PDF_ENABLE_XFA
 
   pDevice->RestoreState(false);
   delete options.m_pOCContext;
 #ifdef PDF_ENABLE_XFA
-  options.m_pOCContext = NULL;
+  options.m_pOCContext = nullptr;
 #endif  // PDF_ENABLE_XFA
 }
 
 }  // namespace
 
 DLLEXPORT int STDCALL FPDFPage_HasFormFieldAtPoint(FPDF_FORMHANDLE hHandle,
                                                    FPDF_PAGE page,
                                                    double page_x,
                                                    double page_y) {
   if (!hHandle)
@@ skipping 106 matching lines @@
 DLLEXPORT void STDCALL
 FPDFDOC_ExitFormFillEnvironment(FPDF_FORMHANDLE hHandle) {
   if (!hHandle)
     return;
   CPDFDoc_Environment* pEnv = (CPDFDoc_Environment*)hHandle;
 #ifdef PDF_ENABLE_XFA
   CPDFXFA_App* pApp = CPDFXFA_App::GetInstance();
   pApp->RemoveFormFillEnv(pEnv);
 #else   // PDF_ENABLE_XFA
   if (CPDFSDK_Document* pSDKDoc = pEnv->GetSDKDocument()) {
-    pEnv->SetSDKDocument(NULL);
+    pEnv->SetSDKDocument(nullptr);
     delete pSDKDoc;
   }
 #endif  // PDF_ENABLE_XFA
   delete pEnv;
 }
 
 DLLEXPORT FPDF_BOOL STDCALL FORM_OnMouseMove(FPDF_FORMHANDLE hHandle,
                                              FPDF_PAGE page,
                                              int modifier,
                                              double page_x,
@@ skipping 438 matching lines @@
         pActionHandler->DoAction_Page(action, CPDF_AAction::OpenPage, pSDKDoc);
       }
     } else {
       if (aa.ActionExist(CPDF_AAction::ClosePage)) {
         CPDF_Action action = aa.GetAction(CPDF_AAction::ClosePage);
         pActionHandler->DoAction_Page(action, CPDF_AAction::ClosePage, pSDKDoc);
       }
     }
   }
 }