--- a/dom/media/MediaStreamGraph.cpp
+++ b/dom/media/MediaStreamGraph.cpp
@@ -3487,21 +3487,16 @@ MediaStreamGraphImpl::CollectReports(nsI
     NS_ENSURE_SUCCESS(rv, rv);                                              \
   } while (0)
 
   for (size_t i = 0; i < mAudioStreamSizes.Length(); i++) {
     const AudioNodeSizes& usage = mAudioStreamSizes[i];
     const char* const nodeType =
       usage.mNodeType ? usage.mNodeType : "<unknown>";
 
-    nsPrintfCString domNodePath("explicit/webaudio/audio-node/%s/dom-nodes",
-                                nodeType);
-    REPORT(domNodePath, usage.mDomNode,
-           "Memory used by AudioNode DOM objects (Web Audio).");
-
     nsPrintfCString enginePath("explicit/webaudio/audio-node/%s/engine-objects",
                                nodeType);
     REPORT(enginePath, usage.mEngine,
            "Memory used by AudioNode engine objects (Web Audio).");
 
     nsPrintfCString streamPath("explicit/webaudio/audio-node/%s/stream-objects",
                                nodeType);
     REPORT(streamPath, usage.mStream,

--- a/dom/media/MediaStreamGraph.h
+++ b/dom/media/MediaStreamGraph.h
@@ -427,18 +427,17 @@ public:
   virtual void NotifyMainThreadStreamFinished() = 0;
 };
 
 /**
  * Helper struct used to keep track of memory usage by AudioNodes.
  */
 struct AudioNodeSizes
 {
-  AudioNodeSizes() : mDomNode(0), mStream(0), mEngine(0), mNodeType() {}
-  size_t mDomNode;
+  AudioNodeSizes() : mStream(0), mEngine(0), mNodeType() {}
   size_t mStream;
   size_t mEngine;
   const char* mNodeType;
 };
 
 class MediaStreamGraphImpl;
 class SourceMediaStream;
 class ProcessedMediaStream;

--- a/dom/media/webaudio/AudioContext.cpp
+++ b/dom/media/webaudio/AudioContext.cpp
@@ -34,16 +34,17 @@
 #include "MediaElementAudioSourceNode.h"
 #include "MediaStreamAudioDestinationNode.h"
 #include "MediaStreamAudioSourceNode.h"
 #include "MediaStreamGraph.h"
 #include "nsContentUtils.h"
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsPIDOMWindow.h"
+#include "nsPrintfCString.h"
 #include "OscillatorNode.h"
 #include "PannerNode.h"
 #include "PeriodicWave.h"
 #include "ScriptProcessorNode.h"
 #include "StereoPannerNode.h"
 #include "WaveShaperNode.h"
 
 namespace mozilla {
@@ -1124,19 +1125,34 @@ AudioContext::SizeOfIncludingThis(mozill
   amount += mPannerNodes.ShallowSizeOfExcludingThis(aMallocSizeOf);
   return amount;
 }
 
 NS_IMETHODIMP
 AudioContext::CollectReports(nsIHandleReportCallback* aHandleReport,
                              nsISupports* aData, bool aAnonymize)
 {
+  const nsLiteralCString
+    nodeDescription("Memory used by AudioNode DOM objects (Web Audio).");
+  for (auto iter = mAllNodes.ConstIter(); !iter.Done(); iter.Next()) {
+    AudioNode* node = iter.Get()->GetKey();
+    int64_t amount = node->SizeOfIncludingThis(MallocSizeOf);
+    nsPrintfCString domNodePath("explicit/webaudio/audio-node/%s/dom-nodes",
+                                node->NodeType());
+    nsresult rv =
+      aHandleReport->Callback(EmptyCString(), domNodePath, KIND_HEAP,
+                              UNITS_BYTES, amount, nodeDescription, aData);
+    if (NS_WARN_IF(NS_FAILED(rv)))
+      return rv;
+  }
+
   int64_t amount = SizeOfIncludingThis(MallocSizeOf);
-  return MOZ_COLLECT_REPORT("explicit/webaudio/audiocontext", KIND_HEAP, UNITS_BYTES,
-                            amount, "Memory used by AudioContext objects (Web Audio).");
+  return MOZ_COLLECT_REPORT("explicit/webaudio/audiocontext",
+                            KIND_HEAP, UNITS_BYTES, amount,
+                            "Memory used by AudioContext objects (Web Audio).");
 }
 
 BasicWaveFormCache*
 AudioContext::GetBasicWaveFormCache()
 {
   MOZ_ASSERT(NS_IsMainThread());
   if (!mBasicWaveFormCache) {
     mBasicWaveFormCache = new BasicWaveFormCache(SampleRate());

--- a/dom/media/webaudio/AudioNodeEngine.h
+++ b/dom/media/webaudio/AudioNodeEngine.h
@@ -391,23 +391,20 @@ public:
     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
   }
 
   void SizeOfIncludingThis(MallocSizeOf aMallocSizeOf,
                            AudioNodeSizes& aUsage) const
   {
     aUsage.mEngine = SizeOfIncludingThis(aMallocSizeOf);
     aUsage.mNodeType = mNodeType;
-    if (mNode) {
-      aUsage.mDomNode = mNode->SizeOfIncludingThis(aMallocSizeOf);
-    }
   }
 
 private:
-  dom::AudioNode* mNode;
+  dom::AudioNode* mNode; // main thread only
   const char* const mNodeType;
   const uint16_t mInputCount;
   const uint16_t mOutputCount;
 };
 
 } // namespace mozilla
 
 #endif /* MOZILLA_AUDIONODEENGINE_H_ */