Do not return a Minikin font collection if the SkFontStyleSet is unable to...

Do not return a Minikin font collection if the SkFontStyleSet is unable to create any typefaces (#24951)

lib/ui/text/asset_manager_font_provider.cc

@@ -117,6 +117,8 @@ SkTypeface* AssetManagerFontStyleSet::createTypeface(int i) {
     // Ownership of the stream is transferred.
     asset.typeface = SkTypeface::MakeFromStream(std::move(stream));
     if (!asset.typeface) {
+      FML_DLOG(ERROR) << "Unable to load font asset for family: "
+                      << family_name_;
       return nullptr;
     }
   }

third_party/txt/src/txt/font_collection.cc

@@ -295,6 +295,10 @@ std::shared_ptr<minikin::FontFamily> FontCollection::CreateMinikinFontFamily(
     }
   }
 
+  if (skia_typefaces.empty()) {
+    return nullptr;
+  }
+
   SortSkTypefaces(skia_typefaces);
 
   std::vector<minikin::Font> minikin_fonts;