--- a/toolkit/crashreporter/ThreadAnnotation.cpp
+++ b/toolkit/crashreporter/ThreadAnnotation.cpp
@@ -194,31 +194,16 @@ private:
   nsCString mData;
 
   // This array tracks the created ThreadAnnotationSpan instances so that we
   // can make adjustments accordingly when we cut substrings from mData on
   // thread exit.
   nsTArray<ThreadAnnotationSpan*> mDataSpans;
 };
 
-template<typename T>
-class DeleteWithLock
-{
-public:
-  constexpr DeleteWithLock() {}
-
-  void operator()(T* aPtr) const
-  {
-    static_assert(sizeof(T) > 0, "T must be complete");
-    CrashReporterAutoLock lock(sMutex);
-
-    delete aPtr;
-  }
-};
-
 static bool sInitialized = false;
 static UniquePtr<ThreadAnnotationData> sThreadAnnotations;
 
 static unsigned sTLSThreadInfoKey = (unsigned) -1;
 void ThreadLocalDestructor(void* aUserData)
 {
   MOZ_ASSERT(aUserData);