Extern in .cpp files is a code smell.

core/src/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 <limits>
 
 #include "../../../include/fxge/fx_ge.h"
 #include "../../../include/fxge/fx_freetype.h"
+#include "../fontdata/chromefontdata/chromefontdata.h"
 #include "text_int.h"
 
 #define GET_TT_SHORT(w) (FX_WORD)(((w)[0] << 8) | (w)[1])
 #define GET_TT_LONG(w) \
   (FX_DWORD)(((w)[0] << 24) | ((w)[1] << 16) | ((w)[2] << 8) | (w)[3])
 
 namespace {
 
 CFX_ByteString KeyNameFromFace(const CFX_ByteString& face_name,
                                int weight,
@@ skipping 364 matching lines @@
     return;
   }
   auto it = m_FaceMap.begin();
   while (it != m_FaceMap.end()) {
     auto temp = it++;
     if (temp->second->ReleaseFace(face)) {
       m_FaceMap.erase(temp);
     }
   }
 }
-extern "C" {
-extern const unsigned char g_FoxitFixedItalicFontData[18746];
-extern const unsigned char g_FoxitFixedFontData[17597];
-extern const unsigned char g_FoxitSansItalicFontData[16339];
-extern const unsigned char g_FoxitSansFontData[15025];
-extern const unsigned char g_FoxitSerifItalicFontData[21227];
-extern const unsigned char g_FoxitSerifFontData[19469];
-extern const unsigned char g_FoxitFixedBoldItalicFontData[19151];
-extern const unsigned char g_FoxitFixedBoldFontData[18055];
-extern const unsigned char g_FoxitSansBoldItalicFontData[16418];
-extern const unsigned char g_FoxitSansBoldFontData[16344];
-extern const unsigned char g_FoxitSerifBoldItalicFontData[20733];
-extern const unsigned char g_FoxitSerifBoldFontData[19395];
-extern const unsigned char g_FoxitSymbolFontData[16729];
-extern const unsigned char g_FoxitDingbatsFontData[29513];
-extern const unsigned char g_FoxitSerifMMFontData[113417];
-extern const unsigned char g_FoxitSansMMFontData[66919];
-};
 const FoxitFonts g_FoxitFonts[14] = {
     {g_FoxitFixedFontData, 17597},
     {g_FoxitFixedBoldFontData, 18055},
     {g_FoxitFixedBoldItalicFontData, 19151},
     {g_FoxitFixedItalicFontData, 18746},
     {g_FoxitSansFontData, 15025},
     {g_FoxitSansBoldFontData, 16344},
     {g_FoxitSansBoldItalicFontData, 16418},
     {g_FoxitSansItalicFontData, 16339},
     {g_FoxitSerifFontData, 19469},
@@ skipping 1070 matching lines @@
   if (hFont == NULL) {
     return FALSE;
   }
   CFX_FontFaceInfo* pFont = (CFX_FontFaceInfo*)hFont;
   name = pFont->m_FaceName;
   return TRUE;
 }
 FX_BOOL CFX_FolderFontInfo::GetFontCharset(void* hFont, int& charset) {
   return FALSE;
 }