Get rid of most instance of 'foo == NULL'

fpdfsdk/src/fpdf_transformpage.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_transformpage.h"
 
 #include "fpdfsdk/include/fsdk_define.h"
 
@@ skipping 177 matching lines @@
 
 DLLEXPORT void STDCALL
 FPDFPageObj_TransformClipPath(FPDF_PAGEOBJECT page_object,
                               double a,
                               double b,
                               double c,
                               double d,
                               double e,
                               double f) {
   CPDF_PageObject* pPageObj = (CPDF_PageObject*)page_object;
-  if (pPageObj == NULL)
+  if (!pPageObj)
     return;
   CFX_Matrix matrix((FX_FLOAT)a, (FX_FLOAT)b, (FX_FLOAT)c, (FX_FLOAT)d,
                     (FX_FLOAT)e, (FX_FLOAT)f);
 
   // Special treatment to shading object, because the ClipPath for shading
   // object is already transformed.
   if (pPageObj->m_Type != PDFPAGE_SHADING)
     pPageObj->TransformClipPath(matrix);
   pPageObj->TransformGeneralState(matrix);
 }
@@ skipping 10 matching lines @@
   pNewClipPath->AppendPath(Path, FXFILL_ALTERNATE, FALSE);
   return pNewClipPath;
 }
 
 DLLEXPORT void STDCALL FPDF_DestroyClipPath(FPDF_CLIPPATH clipPath) {
   delete (CPDF_ClipPath*)clipPath;
 }
 
 void OutputPath(CFX_ByteTextBuf& buf, CPDF_Path path) {
   const CFX_PathData* pPathData = path;
-  if (pPathData == NULL)
+  if (!pPathData)
     return;
 
   FX_PATHPOINT* pPoints = pPathData->GetPoints();
 
   if (path.IsRect()) {
     buf << (pPoints[0].m_PointX) << " " << (pPoints[0].m_PointY) << " "
         << (pPoints[2].m_PointX - pPoints[0].m_PointX) << " "
         << (pPoints[2].m_PointY - pPoints[0].m_PointY) << " re\n";
     return;
   }
@@ skipping 76 matching lines @@
       } else if (pDirectObj->IsStream()) {
         pContentArray = new CPDF_Array();
         pContentArray->AddReference(pDoc, pStream->GetObjNum());
         pContentArray->AddReference(pDoc, pDirectObj->GetObjNum());
         pPageDic->SetAtReference("Contents", pDoc,
                                  pDoc->AddIndirectObject(pContentArray));
       }
     }
   }
 }