Remove "this==NULL" and adjust corresponding callers

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.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 "../../../include/fxge/fx_ge.h"
 #include "../../../include/fxcodec/fx_codec.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_render.h"
@@ skipping 896 matching lines @@
             } else {
                 m_pColorSpace->GetRGB(color_value, R, G, B);
             }
             SetPaletteArgb(i, ArgbEncode(255, FXSYS_round(R * 255), FXSYS_round(G * 255), FXSYS_round(B * 255)));
         }
     }
 }
 FX_DWORD CPDF_DIBSource::GetValidBpp() const
 {
     FX_DWORD bpc = m_bpc;
-    CPDF_Object * pFilter = m_pDict->GetElementValue(FX_BSTRC("Filter"));
+        CPDF_Object * pFilter = m_pDict ? m_pDict->GetElementValue(FX_BSTRC("Filter")) : NULL;
     if (pFilter) {
         if (pFilter->GetType() == PDFOBJ_NAME) {
             CFX_ByteString filter = pFilter->GetString();
             if (filter == FX_BSTRC("CCITTFaxDecode") || filter == FX_BSTRC("JBIG2Decode")) {
                 bpc = 1;
             }
             if (filter == FX_BSTRC("RunLengthDecode") || filter == FX_BSTRC("DCTDecode")) {
                 bpc = 8;
             }
         } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
@@ skipping 579 matching lines @@
     if (!m_bCached) {
         if (m_pBitmap) {
             delete m_pBitmap;
             m_pBitmap = NULL;
         }
         if (m_pMask) {
             delete m_pMask;
         }
     }
 }