Mark CPDF_Font::GlyphFromCharCodeExt() and friends Mac only.

Change-Id: I4906351a6e21fb8480670a6daf15bd7cb9e441c5
Reviewed-on: https://pdfium-review.googlesource.com/39911
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Nicolás Peña Moreno <npm@chromium.org>
diff --git a/core/fpdfapi/font/cpdf_font.cpp b/core/fpdfapi/font/cpdf_font.cpp
index f75f696..f2aa4da 100644
--- a/core/fpdfapi/font/cpdf_font.cpp
+++ b/core/fpdfapi/font/cpdf_font.cpp
@@ -112,9 +112,11 @@
   return pString.GetLength();
 }
 
+#if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
 int CPDF_Font::GlyphFromCharCodeExt(uint32_t charcode) {
   return GlyphFromCharCode(charcode, nullptr);
 }
+#endif
 
 bool CPDF_Font::IsVertWriting() const {
   const CPDF_CIDFont* pCIDFont = AsCIDFont();
diff --git a/core/fpdfapi/font/cpdf_font.h b/core/fpdfapi/font/cpdf_font.h
index f5d0bac..53e5b7b 100644
--- a/core/fpdfapi/font/cpdf_font.h
+++ b/core/fpdfapi/font/cpdf_font.h
@@ -58,7 +58,9 @@
   virtual size_t CountChar(const ByteStringView& pString) const;
   virtual int AppendChar(char* buf, uint32_t charcode) const;
   virtual int GlyphFromCharCode(uint32_t charcode, bool* pVertGlyph) = 0;
+#if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
   virtual int GlyphFromCharCodeExt(uint32_t charcode);
+#endif
   virtual WideString UnicodeFromCharCode(uint32_t charcode) const;
   virtual uint32_t CharCodeFromUnicode(wchar_t Unicode) const;
   virtual bool HasFontWidths() const;
diff --git a/core/fpdfapi/font/cpdf_simplefont.cpp b/core/fpdfapi/font/cpdf_simplefont.cpp
index f1bbf69..dd1a1f3 100644
--- a/core/fpdfapi/font/cpdf_simplefont.cpp
+++ b/core/fpdfapi/font/cpdf_simplefont.cpp
@@ -32,7 +32,6 @@
     : CPDF_Font(pDocument, pFontDict) {
   memset(m_CharWidth, 0xff, sizeof(m_CharWidth));
   memset(m_GlyphIndex, 0xff, sizeof(m_GlyphIndex));
-  memset(m_ExtGID, 0xff, sizeof(m_ExtGID));
   for (size_t i = 0; i < FX_ArraySize(m_CharBBox); ++i)
     m_CharBBox[i] = FX_RECT(-1, -1, -1, -1);
 }
diff --git a/core/fpdfapi/font/cpdf_simplefont.h b/core/fpdfapi/font/cpdf_simplefont.h
index 4c813a2..290016b 100644
--- a/core/fpdfapi/font/cpdf_simplefont.h
+++ b/core/fpdfapi/font/cpdf_simplefont.h
@@ -44,7 +44,6 @@
   bool m_bUseFontWidth;
   std::vector<ByteString> m_CharNames;
   uint16_t m_GlyphIndex[256];
-  uint16_t m_ExtGID[256];
   uint16_t m_CharWidth[256];
   FX_RECT m_CharBBox[256];
 };
diff --git a/core/fpdfapi/font/cpdf_type1font.cpp b/core/fpdfapi/font/cpdf_type1font.cpp
index 8d0eafc..9e2f4ef 100644
--- a/core/fpdfapi/font/cpdf_type1font.cpp
+++ b/core/fpdfapi/font/cpdf_type1font.cpp
@@ -62,7 +62,11 @@
 
 CPDF_Type1Font::CPDF_Type1Font(CPDF_Document* pDocument,
                                CPDF_Dictionary* pFontDict)
-    : CPDF_SimpleFont(pDocument, pFontDict) {}
+    : CPDF_SimpleFont(pDocument, pFontDict) {
+#if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
+  memset(m_ExtGID, 0xff, sizeof(m_ExtGID));
+#endif
+}
 
 CPDF_Type1Font::~CPDF_Type1Font() = default;
 
@@ -102,16 +106,15 @@
   return LoadCommon();
 }
 
+#if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
 int CPDF_Type1Font::GlyphFromCharCodeExt(uint32_t charcode) {
-  if (charcode > 0xff) {
+  if (charcode > 0xff)
     return -1;
-  }
-  int index = m_ExtGID[(uint8_t)charcode];
-  if (index == 0xffff) {
-    return -1;
-  }
-  return index;
+
+  int index = m_ExtGID[static_cast<uint8_t>(charcode)];
+  return index != 0xffff ? index : -1;
 }
+#endif
 
 void CPDF_Type1Font::LoadGlyphMap() {
   if (!m_Font.GetFace())
diff --git a/core/fpdfapi/font/cpdf_type1font.h b/core/fpdfapi/font/cpdf_type1font.h
index 6883461..eaabaae 100644
--- a/core/fpdfapi/font/cpdf_type1font.h
+++ b/core/fpdfapi/font/cpdf_type1font.h
@@ -19,7 +19,9 @@
   bool IsType1Font() const override;
   const CPDF_Type1Font* AsType1Font() const override;
   CPDF_Type1Font* AsType1Font() override;
+#if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
   int GlyphFromCharCodeExt(uint32_t charcode) override;
+#endif
 
   int GetBase14Font() const { return m_Base14Font; }
 
@@ -33,6 +35,8 @@
 #if _FX_PLATFORM_ == _FX_PLATFORM_APPLE_
   void SetExtGID(const char* name, int charcode);
   void CalcExtGID(int charcode);
+
+  uint16_t m_ExtGID[256];
 #endif
 
   int m_Base14Font = -1;