Fix clang_use_chrome_plugin for Mac and Skia builds

core/fxge/apple/fx_mac_imp.cpp

Index: core/fxge/apple/fx_mac_imp.cpp
diff --git a/core/fxge/apple/fx_mac_imp.cpp b/core/fxge/apple/fx_mac_imp.cpp
index a0f2acb37056387246d20c990166240f0a16b298..528b7274dbf31a9adc79d317bd76788549901eb9 100644
--- a/core/fxge/apple/fx_mac_imp.cpp
+++ b/core/fxge/apple/fx_mac_imp.cpp
@@ -25,15 +25,18 @@ static const struct {
     {"Times-BoldItalic", "Times New Roman Bold Italic"},
     {"Times-Italic", "Times New Roman Italic"},
 };
+
 class CFX_MacFontInfo : public CFX_FolderFontInfo {
  public:
-  virtual void* MapFont(int weight,
-                        FX_BOOL bItalic,
-                        int charset,
-                        int pitch_family,
-                        const FX_CHAR* family,
-                        int& iExact);
+  // CFX_FolderFontInfo
+  void* MapFont(int weight,
+                FX_BOOL bItalic,
+                int charset,
+                int pitch_family,
+                const FX_CHAR* family,
+                int& iExact) override;
 };
+
 #define JAPAN_GOTHIC "Hiragino Kaku Gothic Pro W6"
 #define JAPAN_MINCHO "Hiragino Mincho Pro W6"
 static void GetJapanesePreference(CFX_ByteString& face,