Dartifying dart:html type names.

tests/html/audiocontext_test.dart

 library AudioContextTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
 import 'dart:web_audio';
 
 main() {
 
   useHtmlConfiguration();
 
   var isAudioContext =
       predicate((x) => x is AudioContext, 'is an AudioContext');
 
   test('constructorTest', () {
       var ctx = new AudioContext();
       expect(ctx, isNotNull);
       expect(ctx, isAudioContext);
   });
   test('createBuffer', () {
       var ctx = new AudioContext();
       ArrayBufferView arrayBufferView = new Float32Array.fromList([]);
       try {
         // Test that native overload is chosen correctly. Native implementation
-        // should throw 'SYNTAX_ERR' DOMException because the buffer is empty.
+        // should throw 'SYNTAX_ERR' DomException because the buffer is empty.
         AudioBuffer buffer = ctx.createBuffer(arrayBufferView.buffer, false);
       } catch (e) {
-        expect(e.code, equals(DOMException.SYNTAX_ERR));
+        expect(e.code, equals(DomException.SYNTAX_ERR));
       }
   });
 
   test('audioRenames', () {
     AudioContext context = new AudioContext();
     GainNode gainNode = context.createGain();
     gainNode.connect(context.destination, 0, 0);
     expect(gainNode is GainNode, isTrue);
 
     expect(context.createAnalyser() is AnalyserNode, isTrue);
     expect(context.createChannelMerger() is ChannelMergerNode, isTrue);
     expect(context.createChannelSplitter() is ChannelSplitterNode, isTrue);
     expect(context.createOscillator() is OscillatorNode, isTrue);
     expect(context.createPanner() is PannerNode, isTrue);
     expect(context.createScriptProcessor(4096) is ScriptProcessorNode, isTrue);
   });
 }