--- a/dom/media/MediaEventSource.h
+++ b/dom/media/MediaEventSource.h
@@ -4,17 +4,16 @@
  * 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 MediaEventSource_h_
 #define MediaEventSource_h_
 
 #include "mozilla/AbstractThread.h"
 #include "mozilla/Atomics.h"
-#include "mozilla/IndexSequence.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/Tuple.h"
 #include "mozilla/TypeTraits.h"
 #include "mozilla/Unused.h"
 
 #include "nsISupportsImpl.h"
 #include "nsTArray.h"
 #include "nsThreadUtils.h"

deleted file mode 100644
--- a/mfbt/IndexSequence.h
+++ /dev/null
@@ -1,143 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-/* A utility for expanding a tuple into a variadic argument list.
- * Based on std::index_sequence. */
-
-/**
- * Example usage:
- *
- * Problem:
- *
- *   You have a variadic function Foo:
- *
- *     template <typename... Args> void Foo(Args...);
- *
- *   And a variadic function Bar, which contains a tuple:
- *
- *     template <typename... Args>
- *     void Bar() {
- *       // ...
- *       Tuple<Args...> t;
- *     }
- *
- *   And inside Bar, you want to call Foo with the elements of the tuple as
- *   arguments to Foo.
- *
- *   You want to write:
- *
- *     Foo(Get<0>(t), Get<1>(t), ..., Get<N>(t))
- *
- *   but you can't literally write that, because N is different for different
- *   instantiations of Bar.
- *
- * Solution:
- *
- *   Write a helper function which takes the tuple, and an index sequence
- *   containing indices corresponding to the tuple indices.
- *
- *     template <typename... Args, size_t... Indices>
- *     void Helper(const Tuple<Args...>& t, IndexSequence<Indices...>)
- *     {
- *       Foo(Get<Indices>(t)...);
- *     }
- *
- *   Assuming 'Indices...' are 0, 1, ..., N - 1, where N is the size of the
- *   tuple, pack expansion will expand the pack 'Get<Indices>(t)...' to
- *   'Get<0>(t), Get<1>(t), ..., Get<N>(t)'.
- *
- *   Finally, call the helper, creating the index sequence to pass in like so:
- *
- *     template <typename... Args>
- *     void Bar() {
- *       // ...
- *       Tuple<Args...> t;
- *       Helper(t, typename IndexSequenceFor<Args...>::Type());
- *     }
- */
-
-#ifndef mozilla_IndexSequence_h
-#define mozilla_IndexSequence_h
-
-#include "mozilla/Attributes.h"
-
-#include <stddef.h>
-
-namespace mozilla {
-
-/**
- * Represents a compile-time sequence of integer indices.
- */
-template<size_t... Indices>
-struct IndexSequence
-{
-  static constexpr size_t Size() { return sizeof...(Indices); }
-};
-
-namespace detail {
-
-// Helpers used by MakeIndexSequence.
-
-template<size_t... Indices>
-struct IndexTuple
-{
-  typedef IndexTuple<Indices..., sizeof...(Indices)> Next;
-};
-
-// Builds IndexTuple<0, 1, ..., N - 1>.
-template<size_t N>
-struct BuildIndexTuple
-{
-  typedef typename BuildIndexTuple<N - 1>::Type::Next Type;
-};
-
-template<>
-struct BuildIndexTuple<0>
-{
-  typedef IndexTuple<> Type;
-};
-
-template<size_t N, typename IndexTuple>
-struct MakeIndexSequenceImpl;
-
-template<size_t N, size_t... Indices>
-struct MakeIndexSequenceImpl<N, IndexTuple<Indices...>>
-{
-  typedef IndexSequence<Indices...> Type;
-};
-
-} // namespace detail
-
-/**
- * A utility for building an IndexSequence of consecutive indices.
- * MakeIndexSequence<N>::Type evaluates to IndexSequence<0, 1, .., N - 1>.
- * Note: unlike std::make_index_sequence, this is not an alias template
- * to work around bugs in MSVC 2013.
- */
-template<size_t N>
-struct MakeIndexSequence
-{
-  typedef typename detail::MakeIndexSequenceImpl<N,
-    typename detail::BuildIndexTuple<N>::Type>::Type Type;
-};
-
-/**
- * A utility for building an IndexSequence of consecutive indices
- * corresponding to a variadic argument list.
- * IndexSequenceFor<Types...> evaluates to IndexSequence<0, 1, ..., N - 1>
- * where N is the number of types in Types.
- * Note: unlike std::index_sequence_for, this is not an alias template
- * to work around bugs in MSVC 2013.
- */
-template<typename... Types>
-struct IndexSequenceFor
-{
-  typedef typename MakeIndexSequence<sizeof...(Types)>::Type Type;
-};
-
-} // namespace mozilla
-
-#endif /* mozilla_IndexSequence_h */

--- a/mfbt/moz.build
+++ b/mfbt/moz.build
@@ -39,17 +39,16 @@ EXPORTS.mozilla = [
     'EnumeratedRange.h',
     'EnumSet.h',
     'EnumTypeTraits.h',
     'FastBernoulliTrial.h',
     'FloatingPoint.h',
     'FStream.h',
     'GuardObjects.h',
     'HashFunctions.h',
-    'IndexSequence.h',
     'IntegerPrintfMacros.h',
     'IntegerRange.h',
     'IntegerTypeTraits.h',
     'JSONWriter.h',
     'Likely.h',
     'LinkedList.h',
     'MacroArgs.h',
     'MacroForEach.h',

--- a/obj-i686-pc-mingw32/dist/include/MediaEventSource.h
+++ b/obj-i686-pc-mingw32/dist/include/MediaEventSource.h
@@ -4,17 +4,16 @@
  * 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 MediaEventSource_h_
 #define MediaEventSource_h_
 
 #include "mozilla/AbstractThread.h"
 #include "mozilla/Atomics.h"
-#include "mozilla/IndexSequence.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/Tuple.h"
 #include "mozilla/TypeTraits.h"
 #include "mozilla/Unused.h"
 
 #include "nsISupportsImpl.h"
 #include "nsTArray.h"
 #include "nsThreadUtils.h"

--- a/obj-i686-pc-mingw32/dist/include/mozilla/MozPromise.h
+++ b/obj-i686-pc-mingw32/dist/include/mozilla/MozPromise.h
@@ -2,17 +2,16 @@
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* 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/. */
 
 #if !defined(MozPromise_h_)
 #define MozPromise_h_
 
-#include "mozilla/IndexSequence.h"
 #include "mozilla/Logging.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/Monitor.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/Tuple.h"
 #include "mozilla/TypeTraits.h"
 #include "mozilla/Variant.h"