Fix all the code which has duplicate variable declarations

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 "core/fxcodec/codec/codec_int.h"
 #include "core/fxcodec/include/fx_codec.h"
 
 namespace {
@@ skipping 341 matching lines @@
           }
           if (b2 >= columns) {
             return TRUE;
           }
           a0 = b2;
           continue;
         } else {
           if (bitpos >= bitsize) {
             return FALSE;
           }
-          FX_BOOL bit1 = NEXTBIT;
+          FX_BOOL next_bit1 = NEXTBIT;
           if (bitpos >= bitsize) {
             return FALSE;
           }
-          FX_BOOL bit2 = NEXTBIT;
-          if (bit1 && bit2) {
+          FX_BOOL next_bit2 = NEXTBIT;
+          if (next_bit1 && next_bit2) {
             v_delta = 2;
-          } else if (bit1) {
+          } else if (next_bit1) {
             v_delta = -2;
-          } else if (bit2) {
+          } else if (next_bit2) {
             if (bitpos >= bitsize) {
               return FALSE;
             }
             bit = NEXTBIT;
             if (bit) {
               v_delta = 3;
             } else {
               v_delta = -3;
             }
           } else {
@@ skipping 432 matching lines @@
     FX_BOOL EndOfLine,
     FX_BOOL EncodedByteAlign,
     FX_BOOL BlackIs1,
     int Columns,
     int Rows) {
   CCodec_FaxDecoder* pDecoder = new CCodec_FaxDecoder;
   pDecoder->Create(src_buf, src_size, width, height, K, EndOfLine,
                    EncodedByteAlign, BlackIs1, Columns, Rows);
   return pDecoder;
 }