Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

core/fpdfapi/fpdf_page/cpdf_allstates.cpp

 // 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
 
 #include "core/fpdfapi/fpdf_page/cpdf_allstates.h"
 
 #include "core/fpdfapi/fpdf_page/pageint.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
@@ skipping 97 matching lines @@
         }
       case FXBSTR_ID('T', 'R', '2', 0):
         pGeneralState->m_pTR =
             (pObject && !pObject->IsName()) ? pObject : nullptr;
         break;
       case FXBSTR_ID('B', 'M', 0, 0): {
         CPDF_Array* pArray = pObject->AsArray();
         CFX_ByteString mode =
             pArray ? pArray->GetStringAt(0) : pObject->GetString();
 
-        pGeneralState->SetBlendMode(mode);
+        pGeneralState->SetBlendMode(mode.AsByteStringC());
         if (pGeneralState->m_BlendType > FXDIB_BLEND_MULTIPLY) {
           pParser->GetPageObjectHolder()->SetBackgroundAlphaNeeded(TRUE);
         }
         break;
       }
       case FXBSTR_ID('S', 'M', 'a', 's'):
         if (ToDictionary(pObject)) {
           pGeneralState->m_pSoftMask = pObject;
           FXSYS_memcpy(pGeneralState->m_SMaskMatrix,
                        &pParser->GetCurStates()->m_CTM, sizeof(CFX_Matrix));
@@ skipping 48 matching lines @@
       case FXBSTR_ID('A', 'I', 'S', 0):
         pGeneralState->m_AlphaSource = pObject->GetInteger();
         break;
       case FXBSTR_ID('T', 'K', 0, 0):
         pGeneralState->m_TextKnockout = pObject->GetInteger();
         break;
     }
   }
   pGeneralState->m_Matrix = m_CTM;
 }