Remove more question marks.

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 170 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 || when == null) && grainOffset == null && grainDuration == null) {
       _start_1(when);
       return;
     }
-    if ((when is num || when == null) && (grainOffset is num || grainOffset == null) && !?grainDuration) {
+    if ((when is num || when == null) && (grainOffset is num || grainOffset == null) && grainDuration == null) {
       _start_2(when, grainOffset);
       return;
     }
     if ((when is num || when == null) && (grainOffset is num || grainOffset == null) && (grainDuration is num || grainDuration == null)) {
       _start_3(when, grainOffset, grainDuration);
       return;
     }
     throw new ArgumentError("Incorrect number or type of arguments");
   }
 
@@ skipping 53 matching lines @@
   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)) {
       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 ((buffer_OR_numberOfChannels is ByteBuffer || buffer_OR_numberOfChannels == null) && (mixToMono_OR_numberOfFrames is bool || mixToMono_OR_numberOfFrames == null) && sampleRate == null) {
       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')
   @DocsEditable
   AudioBufferSourceNode createBufferSource() native "AudioContext_createBufferSource_Callback";
 
   ChannelMergerNode createChannelMerger([int numberOfInputs]) {
-    if (?numberOfInputs) {
+    if (numberOfInputs != null) {
       return _createChannelMerger_1(numberOfInputs);
     }
     return _createChannelMerger_2();
   }
 
   ChannelMergerNode _createChannelMerger_1(numberOfInputs) native "AudioContext__createChannelMerger_1_Callback";
 
   ChannelMergerNode _createChannelMerger_2() native "AudioContext__createChannelMerger_2_Callback";
 
   ChannelSplitterNode createChannelSplitter([int numberOfOutputs]) {
-    if (?numberOfOutputs) {
+    if (numberOfOutputs != null) {
       return _createChannelSplitter_1(numberOfOutputs);
     }
     return _createChannelSplitter_2();
   }
 
   ChannelSplitterNode _createChannelSplitter_1(numberOfOutputs) native "AudioContext__createChannelSplitter_1_Callback";
 
   ChannelSplitterNode _createChannelSplitter_2() native "AudioContext__createChannelSplitter_2_Callback";
 
   @DomName('AudioContext.createConvolver')
   @DocsEditable
   ConvolverNode createConvolver() native "AudioContext_createConvolver_Callback";
 
   DelayNode createDelay([num maxDelayTime]) {
-    if (?maxDelayTime) {
+    if (maxDelayTime != null) {
       return _createDelay_1(maxDelayTime);
     }
     return _createDelay_2();
   }
 
   DelayNode _createDelay_1(maxDelayTime) native "AudioContext__createDelay_1_Callback";
 
   DelayNode _createDelay_2() native "AudioContext__createDelay_2_Callback";
 
   @DomName('AudioContext.createDynamicsCompressor')
@@ skipping 18 matching lines @@
 
   @DomName('AudioContext.createOscillator')
   @DocsEditable
   OscillatorNode createOscillator() native "AudioContext_createOscillator_Callback";
 
   @DomName('AudioContext.createPanner')
   @DocsEditable
   PannerNode createPanner() native "AudioContext_createPanner_Callback";
 
   ScriptProcessorNode createScriptProcessor(int bufferSize, [int numberOfInputChannels, int numberOfOutputChannels]) {
-    if (?numberOfOutputChannels) {
+    if (numberOfOutputChannels != null) {
       return _createScriptProcessor_1(bufferSize, numberOfInputChannels, numberOfOutputChannels);
     }
-    if (?numberOfInputChannels) {
+    if (numberOfInputChannels != null) {
       return _createScriptProcessor_2(bufferSize, numberOfInputChannels);
     }
     return _createScriptProcessor_3(bufferSize);
   }
 
   ScriptProcessorNode _createScriptProcessor_1(bufferSize, numberOfInputChannels, numberOfOutputChannels) native "AudioContext__createScriptProcessor_1_Callback";
 
   ScriptProcessorNode _createScriptProcessor_2(bufferSize, numberOfInputChannels) native "AudioContext__createScriptProcessor_2_Callback";
 
   ScriptProcessorNode _createScriptProcessor_3(bufferSize) native "AudioContext__createScriptProcessor_3_Callback";
@@ skipping 123 matching lines @@
 
   @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)) {
       _connect_1(destination, output, input);
       return;
     }
-    if ((destination is AudioParam || destination == null) && (output is int || output == null) && !?input) {
+    if ((destination is AudioParam || destination == null) && (output is int || output == null) && input == null) {
       _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 611 matching lines @@
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('WaveTable')
 class WaveTable extends NativeFieldWrapperClass1 {
   WaveTable.internal();
 
 }