Fix some FX_BOOL / int noise in core/fx*

core/fxcodec/codec/fx_codec_fax.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 <algorithm>
 #include <vector>
 
 #include "core/fxcodec/codec/codec_int.h"
@@ skipping 504 matching lines @@
     return nullptr;
 
   FXSYS_memset(m_ScanlineBuf.data(), 0xff, m_ScanlineBuf.size());
   if (m_Encoding < 0) {
     FaxG4GetRow(m_pSrcBuf, bitsize, &m_bitpos, m_ScanlineBuf.data(), m_RefBuf,
                 m_OrigWidth);
     m_RefBuf = m_ScanlineBuf;
   } else if (m_Encoding == 0) {
     FaxGet1DLine(m_pSrcBuf, bitsize, &m_bitpos, &m_ScanlineBuf, m_OrigWidth);
   } else {
-    FX_BOOL bNext1D = m_pSrcBuf[m_bitpos / 8] & (1 << (7 - m_bitpos % 8));
-    ++m_bitpos;
-    if (bNext1D) {
+    if (NextBit(m_pSrcBuf, &m_bitpos)) {
       FaxGet1DLine(m_pSrcBuf, bitsize, &m_bitpos, &m_ScanlineBuf, m_OrigWidth);
     } else {
       FaxG4GetRow(m_pSrcBuf, bitsize, &m_bitpos, m_ScanlineBuf.data(), m_RefBuf,
                   m_OrigWidth);
     }
     m_RefBuf = m_ScanlineBuf;
   }
   if (m_bEndOfLine)
     FaxSkipEOL(m_pSrcBuf, bitsize, &m_bitpos);
 
@@ skipping 62 matching lines @@
     return nullptr;
 
   // Reject unreasonable large input.
   if (actual_width > kMaxImageDimension || actual_height > kMaxImageDimension)
     return nullptr;
 
   uint32_t pitch = (static_cast<uint32_t>(actual_width) + 31) / 32 * 4;
   return new CCodec_FaxDecoder(src_buf, src_size, actual_width, actual_height,
                                pitch, K, EndOfLine, EncodedByteAlign, BlackIs1);
 }