diff --git a/dom/performance/Performance.cpp b/dom/performance/Performance.cpp
index 73cb38f921..09c38fef42 100755
--- a/dom/performance/Performance.cpp
+++ b/dom/performance/Performance.cpp
@@ -542,7 +542,7 @@ Performance::Measure(JSContext* aCx,
   }
 
   RefPtr<PerformanceMeasure> performanceMeasure = new PerformanceMeasure(
-      GetAsISupports(), aName, startTime, endTime, detail);
+      GetParentObject(), aName, startTime, endTime, detail);
   InsertUserEntry(performanceMeasure);
 
   return performanceMeasure.forget();
diff --git a/dom/performance/Performance.h b/dom/performance/Performance.h
index 9966348b8b..6815459dbc 100644
--- a/dom/performance/Performance.h
+++ b/dom/performance/Performance.h
@@ -138,8 +138,6 @@ protected:
   void ClearUserEntries(const Optional<nsAString>& aEntryName,
                         const nsAString& aEntryType);
 
-  virtual nsISupports* GetAsISupports() = 0;
-
   virtual void DispatchBufferFullEvent() = 0;
 
   virtual TimeStamp CreationTimeStamp() const = 0;
diff --git a/dom/performance/PerformanceMainThread.h b/dom/performance/PerformanceMainThread.h
index 702483e9de..735522c502 100644
--- a/dom/performance/PerformanceMainThread.h
+++ b/dom/performance/PerformanceMainThread.h
@@ -65,11 +65,6 @@ public:
 protected:
   ~PerformanceMainThread();
 
-  nsISupports* GetAsISupports() override
-  {
-    return this;
-  }
-
   void InsertUserEntry(PerformanceEntry* aEntry) override;
 
   DOMHighResTimeStamp
diff --git a/dom/performance/PerformanceWorker.h b/dom/performance/PerformanceWorker.h
index 3604e6874f..8dcbf1f202 100644
--- a/dom/performance/PerformanceWorker.h
+++ b/dom/performance/PerformanceWorker.h
@@ -65,11 +65,6 @@ public:
 protected:
   ~PerformanceWorker();
 
-  nsISupports* GetAsISupports() override
-  {
-    return nullptr;
-  }
-
   void InsertUserEntry(PerformanceEntry* aEntry) override;
 
   void DispatchBufferFullEvent() override