From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samuel Attard <samuel.r.attard@gmail.com>
Date: Tue, 17 Nov 2020 16:59:28 -0800
Subject: use public APIs to determine if a font is a system font in MAS build

CTFontDescriptorIsSystemUIFont is a private API, we're using an _interesting_ technique in the MAS build to determine if the font is a system font by checking if it's kCTFontPriorityAttribute is set to system priority.

diff --git a/ui/gfx/platform_font_mac.mm b/ui/gfx/platform_font_mac.mm
index fc6047806e3511f60b58a669fdf628e1a48eb05b..bcc29ac87cfc965eb4c3f06d959605d2cb259770 100644
--- a/ui/gfx/platform_font_mac.mm
+++ b/ui/gfx/platform_font_mac.mm
@@ -25,9 +25,11 @@
 
 using Weight = Font::Weight;
 
+#if !defined(MAS_BUILD)
 extern "C" {
 bool CTFontDescriptorIsSystemUIFont(CTFontDescriptorRef);
 }
+#endif
 
 namespace {
 
@@ -269,7 +271,13 @@ NSInteger ToNSFontManagerWeight(Weight weight) {
   // TODO(avi, etienneb): Figure out this font stuff.
   base::ScopedCFTypeRef<CTFontDescriptorRef> descriptor(
       CTFontCopyFontDescriptor(font));
+#if defined(MAS_BUILD)
+  CFNumberRef priority = (CFNumberRef)CTFontDescriptorCopyAttribute(descriptor.get(), (CFStringRef)kCTFontPriorityAttribute);
+  SInt64 v;
+  if (CFNumberGetValue(priority, kCFNumberSInt64Type, &v) && v == kCTFontPrioritySystem) {
+#else
   if (CTFontDescriptorIsSystemUIFont(descriptor.get())) {
+#endif
     // Assume it's the standard system font. The fact that this much is known is
     // enough.
     return PlatformFontMac::SystemFontType::kGeneral;
