Added tests to previously broken functionality and added null checks.

sdk/lib/web_audio/dartium/web_audio_dartium.dart

 library dart.dom.web_audio;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev';
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:nativewrappers';
 import 'dart:typed_data';
 // DO NOT EDIT
@@ skipping 178 matching lines @@
 
   @DomName('AudioBufferSourceNode.playbackRate')
   @DocsEditable
   AudioParam get playbackRate native "AudioBufferSourceNode_playbackRate_Getter";
 
   @DomName('AudioBufferSourceNode.playbackState')
   @DocsEditable
   int get playbackState native "AudioBufferSourceNode_playbackState_Getter";
 
   void start(num when, [num grainOffset, num grainDuration]) {
-    if ((when is num || when == null) && !?grainOffset && !?grainDuration) {
+    if (when is num && !?grainOffset && !?grainDuration) {

[blois, 2013/05/13 21:09:16]

when is when not a num?

       _start_1(when);
       return;
     }
-    if ((when is num || when == null) && (grainOffset is num || grainOffset == null) && !?grainDuration) {
+    if (grainOffset is num && grainOffset != null && when is num && !?grainDuration) {
       _start_2(when, grainOffset);
       return;
     }
-    if ((when is num || when == null) && (grainOffset is num || grainOffset == null) && (grainDuration is num || grainDuration == null)) {
+    if (grainDuration is num && grainDuration != null && grainOffset is num && grainOffset != null && when is num) {
       _start_3(when, grainOffset, grainDuration);
       return;
     }
     throw new ArgumentError("Incorrect number or type of arguments");
   }
 
   void _start_1(when) native "AudioBufferSourceNode__start_1_Callback";
 
   void _start_2(when, grainOffset) native "AudioBufferSourceNode__start_2_Callback";
 
@@ skipping 46 matching lines @@
 
   @DomName('AudioContext.createAnalyser')
   @DocsEditable
   AnalyserNode createAnalyser() native "AudioContext_createAnalyser_Callback";
 
   @DomName('AudioContext.createBiquadFilter')
   @DocsEditable
   BiquadFilterNode createBiquadFilter() native "AudioContext_createBiquadFilter_Callback";
 
   AudioBuffer createBuffer(buffer_OR_numberOfChannels, mixToMono_OR_numberOfFrames, [num sampleRate]) {
-    if ((buffer_OR_numberOfChannels is int || buffer_OR_numberOfChannels == null) && (mixToMono_OR_numberOfFrames is int || mixToMono_OR_numberOfFrames == null) && (sampleRate is num || sampleRate == null)) {
+    if (sampleRate is num && sampleRate != null && mixToMono_OR_numberOfFrames is int && mixToMono_OR_numberOfFrames != null && buffer_OR_numberOfChannels is int && buffer_OR_numberOfChannels != null) {
       return _createBuffer_1(buffer_OR_numberOfChannels, mixToMono_OR_numberOfFrames, sampleRate);
     }
-    if ((buffer_OR_numberOfChannels is ByteBuffer || buffer_OR_numberOfChannels == null) && (mixToMono_OR_numberOfFrames is bool || mixToMono_OR_numberOfFrames == null) && !?sampleRate) {
+    if (mixToMono_OR_numberOfFrames is bool && mixToMono_OR_numberOfFrames != null && buffer_OR_numberOfChannels is ByteBuffer && buffer_OR_numberOfChannels != null && !?sampleRate) {
       return _createBuffer_2(buffer_OR_numberOfChannels, mixToMono_OR_numberOfFrames);
     }
     throw new ArgumentError("Incorrect number or type of arguments");
   }
 
   AudioBuffer _createBuffer_1(buffer_OR_numberOfChannels, mixToMono_OR_numberOfFrames, sampleRate) native "AudioContext__createBuffer_1_Callback";
 
   AudioBuffer _createBuffer_2(buffer_OR_numberOfChannels, mixToMono_OR_numberOfFrames) native "AudioContext__createBuffer_2_Callback";
 
   @DomName('AudioContext.createBufferSource')
@@ skipping 202 matching lines @@
 
   @DomName('AudioNode.numberOfInputs')
   @DocsEditable
   int get numberOfInputs native "AudioNode_numberOfInputs_Getter";
 
   @DomName('AudioNode.numberOfOutputs')
   @DocsEditable
   int get numberOfOutputs native "AudioNode_numberOfOutputs_Getter";
 
   void connect(destination, int output, [int input]) {
-    if ((destination is AudioNode || destination == null) && (output is int || output == null) && (input is int || input == null)) {
+    if (input is int && input != null && output is int && destination is AudioNode && destination != null) {
       _connect_1(destination, output, input);
       return;
     }
-    if ((destination is AudioParam || destination == null) && (output is int || output == null) && !?input) {
+    if (output is int && destination is AudioParam && destination != null && !?input) {
       _connect_2(destination, output);
       return;
     }
     throw new ArgumentError("Incorrect number or type of arguments");
   }
 
   void _connect_1(destination, output, input) native "AudioNode__connect_1_Callback";
 
   void _connect_2(destination, output) native "AudioNode__connect_2_Callback";
 
@@ skipping 657 matching lines @@
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('WaveTable')
 class WaveTable extends NativeFieldWrapperClass1 {
   WaveTable.internal();
 
 }