Revert of Revert of Remove Mac native font type members from FontPlatformData

Source/web/mac/WebSubstringUtil.mm

Index: Source/web/mac/WebSubstringUtil.mm
diff --git a/Source/web/mac/WebSubstringUtil.mm b/Source/web/mac/WebSubstringUtil.mm
index 07923b5b6d48ecf73133c7170c4cb49d53547b04..a70bacadc60cad41ab2d79ecfb65ef1e82b8a4fc 100644
--- a/Source/web/mac/WebSubstringUtil.mm
+++ b/Source/web/mac/WebSubstringUtil.mm
@@ -78,7 +78,8 @@
             continue;
 
         LayoutStyle* style = renderer->style();
-        NSFont* font = style->font().primaryFont()->getNSFont();
+        const FontPlatformData& fontPlatformData = style->font().primaryFont()->platformData();
+        NSFont* font = toNSFont(fontPlatformData.ctFont());
         // If the platform font can't be loaded, it's likely that the site is
         // using a web font. For now, just use the default font instead.
         // TODO(rsesek): Change the font activation flags to allow other processes