Reduce signed/unsigned comparison warnings

core/fxge/ge/fx_ge_fontmap.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 <limits>
 #include <vector>
 
@@ skipping 1311 matching lines @@
 
 void* IFX_SystemFontInfo::RetainFont(void* hFont) {
   return NULL;
 }
 
 int CFX_FontMapper::GetFaceSize() const {
   return pdfium::CollectionSize<int>(m_FaceArray);
 }
 
 FX_BOOL CFX_FontMapper::IsBuiltinFace(const FXFT_Face face) const {
-  for (int i = 0; i < MM_FACE_COUNT; ++i) {
+  for (size_t i = 0; i < MM_FACE_COUNT; ++i) {
     if (m_MMFaces[i] == face) {
       return TRUE;
     }
   }
-  for (int i = 0; i < FOXIT_FACE_COUNT; ++i) {
+  for (size_t i = 0; i < FOXIT_FACE_COUNT; ++i) {
     if (m_FoxitFaces[i] == face) {
       return TRUE;
     }
   }
   return FALSE;
 }
 
 extern "C" {
 unsigned long _FTStreamRead(FXFT_Stream stream,
                             unsigned long offset,
@@ skipping 294 matching lines @@
 int PDF_GetStandardFontName(CFX_ByteString* name) {
   AltFontName* found = static_cast<AltFontName*>(
       FXSYS_bsearch(name->c_str(), g_AltFontNames, FX_ArraySize(g_AltFontNames),
                     sizeof(AltFontName), CompareString));
   if (!found)
     return -1;
 
   *name = g_Base14FontNames[found->m_Index];
   return found->m_Index;
 }