fix a few linux compilation warnings

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.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/fpdfapi/fpdf_parser.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../../third_party/numerics/safe_math.h"
@@ skipping 616 matching lines @@
         m_pTrailer = NULL;
     }
     FX_INT32 status = 0;
     FX_INT32 inside_index = 0;
     FX_DWORD objnum, gennum;
     FX_INT32 depth = 0;
     FX_LPBYTE buffer = FX_Alloc(FX_BYTE, 4096);
     FX_FILESIZE pos = m_Syntax.m_HeaderOffset;
     FX_FILESIZE start_pos, start_pos1;
     FX_FILESIZE last_obj = -1, last_xref = -1, last_trailer = -1;
+    // TODO(tsepez): unused bInUpdate seems suspicious.
     FX_BOOL bInUpdate = FALSE;
     while (pos < m_Syntax.m_FileLen) {
         FX_BOOL bOverFlow = FALSE;
         FX_DWORD size = (FX_DWORD)(m_Syntax.m_FileLen - pos);
         if (size > 4096) {
             size = 4096;
         }
         if (!m_Syntax.m_pFileAccess->ReadBlock(buffer, pos, size)) {
             break;
         }
@@ skipping 1498 matching lines @@
     }
     if (word[0] == '/') {
         if (bTypeOnly) {
             return (CPDF_Object*)PDFOBJ_NAME;
         }
         pRet = CPDF_Name::Create(PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1)));
         return pRet;
     }
     if (word == FX_BSTRC("<<")) {
         FX_FILESIZE saveDictOffset = m_Pos - 2;
+        // TODO(tsepez): unused dwDictSize seems suspicous.
         FX_DWORD dwDictSize = 0;
         if (bTypeOnly) {
             return (CPDF_Object*)PDFOBJ_DICTIONARY;
         }
         if (pContext) {
             pContext->m_DictStart = SavedPos;
         }
         CPDF_Dictionary* pDict = CPDF_Dictionary::Create();
         FX_INT32 nKeys = 0;
         FX_FILESIZE dwSignValuePos = 0;
@@ skipping 2261 matching lines @@
 {
     FX_INT32 iSize = m_childNode.GetSize();
     for (FX_INT32 i = 0; i < iSize; ++i) {
         CPDF_PageNode *pNode = (CPDF_PageNode*)m_childNode[i];
         if (pNode) {
             delete pNode;
         }
     }
     m_childNode.RemoveAll();
 }