Add constructors for WebAudio nodes

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 438c1764ec4c1ad4fcadb9f6718dc3d3bf6ad79a..0776e3981d44ac9e68c949e34741a6cca75d37c9 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -80794,6 +80794,23 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1554" label="DragAndDropScrollStart"/>
   <int value="1555"
       label="PresentationConnectionListConnectionAvailableEventListener"/>
+  <int value="1556" label="AnalyserNode"/>
+  <int value="1557" label="AudioBuffer"/>
+  <int value="1558" label="AudioBufferSourceNode"/>
+  <int value="1559" label="BiquadFilterNode"/>
+  <int value="1560" label="ChannelMergerNode"/>
+  <int value="1561" label="ChannelSplitterNode"/>
+  <int value="1562" label="ConvolverNode"/>
+  <int value="1563" label="DelayNode"/>
+  <int value="1564" label="DynamicsCompressorNode"/>
+  <int value="1565" label="GainNode"/>
+  <int value="1566" label="IIRFilterNode"/>
+  <int value="1567" label="MediaElementAudioSourceNode"/>
+  <int value="1568" label="OscillatorNode"/>
+  <int value="1569" label="PannerNode"/>
+  <int value="1570" label="PeriodicWave"/>
+  <int value="1571" label="StereoPannerNode"/>
+  <int value="1572" label="WaveShaperNode"/>
 </enum>
 
 <enum name="FetchRequestMode" type="int">