Restrict supported font formats in Chrome context

src/ports/SkFontConfigInterface_direct.cpp

Index: src/ports/SkFontConfigInterface_direct.cpp
diff --git a/src/ports/SkFontConfigInterface_direct.cpp b/src/ports/SkFontConfigInterface_direct.cpp
index 345544724695a1729e1644693199f45f49913148..8fe9898bc719e9cf4be76663ad3769d3caf55422 100644
--- a/src/ports/SkFontConfigInterface_direct.cpp
+++ b/src/ports/SkFontConfigInterface_direct.cpp
@@ -496,6 +496,10 @@ static void fcpattern_from_skfontstyle(SkFontStyle style, FcPattern* pattern) {
 ///////////////////////////////////////////////////////////////////////////////
 
 #define kMaxFontFamilyLength    2048
+#ifdef SK_FONT_CONFIG_INTERFACE_ONLY_ALLOW_SFNT_FONTS
+const char* kFontFormatTrueType = "TrueType";
+const char* kFontFormatCFF = "CFF";
+#endif
 
 SkFontConfigInterfaceDirect::SkFontConfigInterfaceDirect() {
     FCLocker lock;
@@ -524,6 +528,16 @@ bool SkFontConfigInterfaceDirect::isValidPattern(FcPattern* pattern) {
     }
 #endif
 
+#ifdef SK_FONT_CONFIG_INTERFACE_ONLY_ALLOW_SFNT_FONTS
+    const char* font_format = get_name(pattern, FC_FONTFORMAT);
+    if (font_format
+        && strcmp(font_format, kFontFormatTrueType) != 0
+        && strcmp(font_format, kFontFormatCFF) != 0)
+    {
+        return false;
+    }
+#endif
+
     // fontconfig can also return fonts which are unreadable
     const char* c_filename = get_name(pattern, FC_FILE);
     if (!c_filename) {
@@ -593,6 +607,11 @@ bool SkFontConfigInterfaceDirect::matchFamilyName(const char familyName[],
 
     FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
 
+#ifdef SK_FONT_CONFIG_INTERFACE_ONLY_ALLOW_SFNT_FONTS
+    FcPatternAddString(pattern, FC_FONTFORMAT, reinterpret_cast<const FcChar8*>(kFontFormatTrueType));
+    FcPatternAddString(pattern, FC_FONTFORMAT, reinterpret_cast<const FcChar8*>(kFontFormatCFF));
+#endif
+
     FcConfigSubstitute(nullptr, pattern, FcMatchPattern);
     FcDefaultSubstitute(pattern);