Fix more code which has shadow variables

core/fxcodec/lgif/fx_gif.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/lgif/fx_gif.h"
 
 #include "core/fxcodec/lbmp/fx_bmp.h"
 
@@ skipping 316 matching lines @@
       }
     }
   }
   src_offset = 0;
   src_bit_offset = 0;
   src_bit_num = 0;
   return TRUE;
 }
 FX_BOOL CGifLZWEncoder::LookUpInTable(const uint8_t* buf,
                                       uint32_t& offset,
-                                      uint8_t& bit_offset) {
+                                      uint8_t& out_bit_offset) {
   for (uint16_t i = table_cur; i < index_num; i++) {
     if (code_table[i].prefix == code_table[index_num].prefix &&
         code_table[i].suffix == code_table[index_num].suffix) {
       code_table[index_num].prefix = i;
       code_table[index_num].suffix =
-          gif_cut_buf(buf, offset, src_bit_cut, bit_offset, src_bit_num);
+          gif_cut_buf(buf, offset, src_bit_cut, out_bit_offset, src_bit_num);
       table_cur = i;
       return TRUE;
     }
   }
   table_cur = code_end + 1;
   return FALSE;
 }
 void CGifLZWEncoder::Finish(uint8_t*& dst_buf,
                             uint32_t& dst_len,
                             uint32_t& offset) {
@@ skipping 866 matching lines @@
     gif_ptr->cur_offset = cur_offset;
     res = FALSE;
   }
   dst_len = gif_ptr->cur_offset;
   dst_buf[dst_len - 1] = GIF_SIG_TRAILER;
   if (res) {
     gif_ptr->frames++;
   }
   return res;
 }