Update svg tests for removal of AltGlyphElement

tests/html/svgelement_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library SvgElementTest;
 import 'dart:html';
 import 'dart:svg' as svg;
 import 'package:expect/expect.dart';
 import 'package:unittest/html_individual_config.dart';
 import 'package:unittest/unittest.dart';
@@ skipping 52 matching lines @@
       expect(() => new svg.SvgElement.svg(""), throwsStateError);
     });
 
     test('too many elements', () {
       expect(() => new svg.SvgElement.svg("<circle></circle><path></path>"),
           throwsStateError);
     });
   });
 
   // Unfortunately, because the filtering mechanism in unitttest is a regex done
-  group('supported_altGlyph', () {
-    test('supported', () {
-      expect(svg.AltGlyphElement.supported, true);
-    });
-  });
-
   group('supported_animate', () {
     test('supported', () {
       expect(svg.AnimateElement.supported, true);
     });
   });
 
   group('supported_animateMotion', () {
     test('supported', () {
       expect(svg.AnimateMotionElement.supported, true);
     });
@@ skipping 181 matching lines @@
       testConstructor('style', (e) => e is svg.StyleElement);
       testConstructor('switch', (e) => e is svg.SwitchElement);
       testConstructor('symbol', (e) => e is svg.SymbolElement);
       testConstructor('tspan', (e) => e is svg.TSpanElement);
       testConstructor('text', (e) => e is svg.TextElement);
       testConstructor('textPath', (e) => e is svg.TextPathElement);
       testConstructor('title', (e) => e is svg.TitleElement);
       testConstructor('use', (e) => e is svg.UseElement);
       testConstructor('view', (e) => e is svg.ViewElement);
       // TODO(alanknight): Issue 23144
-      testConstructor('altGlyph', (e) => e is svg.AltGlyphElement,
-          svg.AltGlyphElement.supported, false);
       testConstructor('animate', (e) => e is svg.AnimateElement,
           svg.AnimateElement.supported);
       testConstructor('animateMotion', (e) => e is svg.AnimateMotionElement,
           svg.AnimateMotionElement.supported);
       testConstructor('animateTransform', (e) => e is svg.AnimateTransformElement,
           svg.AnimateTransformElement.supported);
       testConstructor('feBlend', (e) => e is svg.FEBlendElement,
           svg.FEBlendElement.supported);
       testConstructor('feColorMatrix', (e) => e is svg.FEColorMatrixElement,
           svg.FEColorMatrixElement.supported);
@@ skipping 181 matching lines @@
   group('PathElement', () {
     test('pathSegList', () {
       svg.PathElement path =
           new svg.SvgElement.svg('<path d="M 100 100 L 300 100 L 200 300 z"/>');
       for (var seg in path.pathSegList) {
         expect(seg is svg.PathSeg, isTrue);
       }
     });
   });
 }