Drop [LegacyInterfaceTypeChecking] where trivial in core/

third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html

Index: third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html
diff --git a/third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html b/third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html
index b754ce99855a65f5f813839982509c1d6c133f45..9d6db69c78d57c44f25e85e4030760d3654e0f0d 100644
--- a/third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html
+++ b/third_party/WebKit/LayoutTests/fast/css/fontfaceset-set-operations.html
@@ -76,8 +76,14 @@ function runTests() {
     }
     checkResults();
 
+    shouldThrow('document.fonts.has(null)');
+    shouldThrow('document.fonts.has("Font1")');
+    shouldThrow('document.fonts.add(null)');
+    shouldThrow('document.fonts.add("Font1")');
+    shouldThrow('document.fonts.delete(null)');
+    shouldThrow('document.fonts.delete("Font1")');
+
     shouldBeFalse('document.fonts.has(nonCssConnectedFace)');
-    shouldThrow('document.fonts.has("Font1")', '"TypeError: Failed to execute \'has\' on \'FontFaceSet\': The argument is not a FontFace."');
 
     shouldNotThrow('document.fonts.add(faces[0])');
     shouldBe('document.fonts.size', '3');