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 edfe252772965e0350e02f6d75f453a54ef84ed6..4196eef78d31158fc35773cfd0f35869fc66da5d 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -81088,6 +81088,23 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1555"
       label="PresentationConnectionListConnectionAvailableEventListener"/>
   <int value="1556" label="WebAudioAutoplayCrossOriginIframe"/>
+  <int value="1557" label="AnalyserNode"/>
+  <int value="1558" label="AudioBuffer"/>
+  <int value="1559" label="AudioBufferSourceNode"/>
+  <int value="1560" label="BiquadFilterNode"/>
+  <int value="1561" label="ChannelMergerNode"/>
+  <int value="1562" label="ChannelSplitterNode"/>
+  <int value="1563" label="ConvolverNode"/>
+  <int value="1564" label="DelayNode"/>
+  <int value="1565" label="DynamicsCompressorNode"/>
+  <int value="1566" label="GainNode"/>
+  <int value="1567" label="IIRFilterNode"/>
+  <int value="1568" label="MediaElementAudioSourceNode"/>
+  <int value="1569" label="OscillatorNode"/>
+  <int value="1570" label="PannerNode"/>
+  <int value="1571" label="PeriodicWave"/>
+  <int value="1572" label="StereoPannerNode"/>
+  <int value="1573" label="WaveShaperNode"/>
 </enum>
 
 <enum name="FetchRequestMode" type="int">