Add all dart:html tests from the sdk to test/codegen.

test/codegen/lib/html/audiocontext_test.dart

+library AudioContextTest;
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_individual_config.dart';
+import 'dart:html';
+import 'dart:typed_data';
+import 'dart:web_audio';
+import 'dart:async';
+
+main() {
+
+  useHtmlIndividualConfiguration();
+
+  var isAudioContext =
+      predicate((x) => x is AudioContext, 'is an AudioContext');
+
+  group('supported', () {
+    test('supported', () {
+      expect(AudioContext.supported, true);
+    });
+  });
+
+  group('functional', () {
+    var context;
+    if (AudioContext.supported) {
+      context = new AudioContext();
+    }
+    
+    test('constructorTest', () {
+      if(AudioContext.supported) {
+        expect(context, isNotNull);
+        expect(context, isAudioContext);
+      }
+    });
+
+    test('audioRenames', () {
+      if(AudioContext.supported) {
+        GainNode gainNode = context.createGain();
+        gainNode.connectNode(context.destination);
+        expect(gainNode is GainNode, isTrue);
+
+        expect(context.createAnalyser() is AnalyserNode, isTrue);
+        expect(context.createChannelMerger() is AudioNode, isTrue);
+        expect(context.createChannelSplitter() is AudioNode, isTrue);
+        expect(context.createOscillator() is OscillatorNode, isTrue);
+        expect(context.createPanner() is PannerNode, isTrue);
+        expect(context.createScriptProcessor(4096) is ScriptProcessorNode,
+            isTrue);
+      }
+    });
+
+    // TODO(9322): This test times out.
+    /*
+    test('onAudioProcess', () {
+      if(AudioContext.supported) {
+        var completer = new Completer<bool>();
+        var context = new AudioContext();
+        var scriptProcessor = context.createScriptProcessor(1024, 1, 2);
+        scriptProcessor.connectNode(context.destination);
+        bool alreadyCalled = false;
+        scriptProcessor.onAudioProcess.listen((event) {
+          if (!alreadyCalled) {
+            completer.complete(true);
+          }
+          alreadyCalled = true;
+        });
+        return completer.future;
+      }
+    });
+    */
+
+    test('oscillatorTypes', () {
+      if(AudioContext.supported) {
+        OscillatorNode oscillator = context.createOscillator();
+        oscillator.connectNode(context.destination);
+
+        oscillator.type = 'sawtooth';
+        expect(oscillator.type, equals('sawtooth'));
+
+        oscillator.type = 'sine';
+        expect(oscillator.type, equals('sine'));
+
+        oscillator.type = 'square';
+        expect(oscillator.type, equals('square'));
+
+        oscillator.type = 'triangle';
+        expect(oscillator.type, equals('triangle'));
+
+        //expect(() => oscillator.type = 7, throws); Firefox does not throw, it
+        //simply ignores this value.
+        expect(oscillator.type, equals('triangle'));
+
+        // Firefox does not throw when it receives invalid values; it simply
+        // ignores them.
+        //expect(() => oscillator.type = ['heap object not a string'], throws);
+        expect(oscillator.type, equals('triangle'));
+      }
+    });
+  });
+}