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diff --git a/dom/media/webaudio/AlignedTArray.h b/dom/media/webaudio/AlignedTArray.h
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+++ b/dom/media/webaudio/AlignedTArray.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef AlignedTArray_h__
+#define AlignedTArray_h__
+
+#include "mozilla/Alignment.h"
+#include "nsTArray.h"
+
+/**
+ * E: element type, must be a POD type.
+ * N: N bytes alignment for the first element, defaults to 32
+ * S: S bytes of inline storage
+ */
+template <typename E, int S, int N = 32>
+class AlignedAutoTArray : private AutoTArray<E, S + N> {
+  static_assert((N & (N - 1)) == 0, "N must be power of 2");
+  typedef AutoTArray<E, S + N> base_type;
+
+ public:
+  typedef E value_type;
+  typedef typename base_type::size_type size_type;
+  typedef typename base_type::index_type index_type;
+
+  AlignedAutoTArray() = default;
+  explicit AlignedAutoTArray(size_type capacity)
+      : base_type(capacity + sExtra) {}
+  value_type* Elements() { return getAligned(base_type::Elements()); }
+  const value_type* Elements() const {
+    return getAligned(base_type::Elements());
+  }
+  value_type& operator[](index_type i) { return Elements()[i]; }
+  const value_type& operator[](index_type i) const { return Elements()[i]; }
+
+  void SetLength(size_type newLen) { base_type::SetLength(newLen + sExtra); }
+
+  [[nodiscard]] bool SetLength(size_type newLen, const mozilla::fallible_t&) {
+    return base_type::SetLength(newLen + sExtra, mozilla::fallible);
+  }
+
+  size_type Length() const {
+    return base_type::Length() <= sExtra ? 0 : base_type::Length() - sExtra;
+  }
+
+  using base_type::ShallowSizeOfExcludingThis;
+  using base_type::ShallowSizeOfIncludingThis;
+
+ private:
+  AlignedAutoTArray(const AlignedAutoTArray& other) = delete;
+  void operator=(const AlignedAutoTArray& other) = delete;
+
+  static const size_type sPadding =
+      N <= MOZ_ALIGNOF(E) ? 0 : N - MOZ_ALIGNOF(E);
+  static const size_type sExtra = (sPadding + sizeof(E) - 1) / sizeof(E);
+
+  template <typename U>
+  static U* getAligned(U* p) {
+    return reinterpret_cast<U*>(((uintptr_t)p + N - 1) & ~(N - 1));
+  }
+};
+
+/**
+ * E: element type, must be a POD type.
+ * N: N bytes alignment for the first element, defaults to 32
+ */
+template <typename E, int N = 32>
+class AlignedTArray : private nsTArray_Impl<E, nsTArrayInfallibleAllocator> {
+  static_assert((N & (N - 1)) == 0, "N must be power of 2");
+  typedef nsTArray_Impl<E, nsTArrayInfallibleAllocator> base_type;
+
+ public:
+  typedef E value_type;
+  typedef typename base_type::size_type size_type;
+  typedef typename base_type::index_type index_type;
+
+  AlignedTArray() = default;
+  explicit AlignedTArray(size_type capacity) : base_type(capacity + sExtra) {}
+  value_type* Elements() { return getAligned(base_type::Elements()); }
+  const value_type* Elements() const {
+    return getAligned(base_type::Elements());
+  }
+  value_type& operator[](index_type i) { return Elements()[i]; }
+  const value_type& operator[](index_type i) const { return Elements()[i]; }
+
+  void SetLength(size_type newLen) { base_type::SetLength(newLen + sExtra); }
+
+  [[nodiscard]] bool SetLength(size_type newLen, const mozilla::fallible_t&) {
+    return base_type::SetLength(newLen + sExtra, mozilla::fallible);
+  }
+
+  size_type Length() const {
+    return base_type::Length() <= sExtra ? 0 : base_type::Length() - sExtra;
+  }
+
+  using base_type::ShallowSizeOfExcludingThis;
+  using base_type::ShallowSizeOfIncludingThis;
+
+ private:
+  AlignedTArray(const AlignedTArray& other) = delete;
+  void operator=(const AlignedTArray& other) = delete;
+
+  static const size_type sPadding =
+      N <= MOZ_ALIGNOF(E) ? 0 : N - MOZ_ALIGNOF(E);
+  static const size_type sExtra = (sPadding + sizeof(E) - 1) / sizeof(E);
+
+  template <typename U>
+  static U* getAligned(U* p) {
+    return reinterpret_cast<U*>(((uintptr_t)p + N - 1) & ~(N - 1));
+  }
+};
+
+#endif  // AlignedTArray_h__