deleted file mode 100644
--- a/dom/media/fmp4/MP4Stream.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-/* -*- 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/. */
-
-#include "MP4Stream.h"
-
-namespace mozilla {
-
-MP4Stream::MP4Stream(MediaResource* aResource)
-  : mResource(aResource)
-{
-  MOZ_COUNT_CTOR(MP4Stream);
-  MOZ_ASSERT(aResource);
-}
-
-MP4Stream::~MP4Stream()
-{
-  MOZ_COUNT_DTOR(MP4Stream);
-}
-
-bool
-MP4Stream::ReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
-                  size_t* aBytesRead)
-{
-  return CachedReadAt(aOffset, aBuffer, aCount, aBytesRead);
-}
-
-bool
-MP4Stream::CachedReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
-                        size_t* aBytesRead)
-{
-  nsresult rv =
-    mResource.GetResource()->ReadFromCache(reinterpret_cast<char*>(aBuffer),
-                                           aOffset, aCount);
-  if (NS_FAILED(rv)) {
-    *aBytesRead = 0;
-    return false;
-  }
-  *aBytesRead = aCount;
-  return true;
-}
-
-bool
-MP4Stream::Length(int64_t* aSize)
-{
-  if (mResource.GetLength() < 0)
-    return false;
-  *aSize = mResource.GetLength();
-  return true;
-}
-
-} // namespace mozilla

deleted file mode 100644
--- a/dom/media/fmp4/MP4Stream.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/* -*- 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 MP4_STREAM_H_
-#define MP4_STREAM_H_
-
-#include "mp4_demuxer/Stream.h"
-
-#include "MediaResource.h"
-
-namespace mozilla {
-
-class MP4Stream : public mp4_demuxer::Stream {
-public:
-  explicit MP4Stream(MediaResource* aResource);
-  virtual ~MP4Stream();
-  bool ReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
-              size_t* aBytesRead) override;
-  bool CachedReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
-                    size_t* aBytesRead) override;
-  bool Length(int64_t* aSize) override;
-
-private:
-  MediaResourceIndex mResource;
-};
-
-} // namespace mozilla
-
-#endif

--- a/dom/media/fmp4/moz.build
+++ b/dom/media/fmp4/moz.build
@@ -2,22 +2,20 @@
 # vim: set filetype=python:
 # 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/.
 
 EXPORTS += [
     'MP4Decoder.h',
     'MP4Demuxer.h',
-    'MP4Stream.h',
 ]
 
 UNIFIED_SOURCES += [
     'MP4Decoder.cpp',
-    'MP4Stream.cpp',
 ]
 
 SOURCES += [
     'MP4Demuxer.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
 

--- a/dom/media/gtest/TestMP4Demuxer.cpp
+++ b/dom/media/gtest/TestMP4Demuxer.cpp
@@ -1,16 +1,15 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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/. */
 
 #include "gtest/gtest.h"
 #include "MP4Demuxer.h"
-#include "MP4Stream.h"
 #include "mozilla/MozPromise.h"
 #include "MediaDataDemuxer.h"
 #include "mozilla/SharedThreadPool.h"
 #include "mozilla/TaskQueue.h"
 #include "mozilla/ArrayUtils.h"
 #include "MockMediaResource.h"
 #include "VideoUtils.h"
 

--- a/dom/media/mediasource/ContainerParser.cpp
+++ b/dom/media/mediasource/ContainerParser.cpp
@@ -11,19 +11,19 @@
 #include "mozilla/IntegerPrintfMacros.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/SizePrintfMacros.h"
 #include "mp4_demuxer/MoofParser.h"
 #include "mozilla/Logging.h"
 #include "mozilla/Maybe.h"
 #include "MediaData.h"
 #ifdef MOZ_FMP4
-#include "MP4Stream.h"
 #include "mp4_demuxer/AtomType.h"
 #include "mp4_demuxer/ByteReader.h"
+#include "mp4_demuxer/Stream.h"
 #endif
 #include "nsAutoPtr.h"
 #include "SourceBufferResource.h"
 #include <algorithm>
 
 extern mozilla::LogModule* GetMediaSourceSamplesLog();
 
 #define STRINGIFY(x) #x
@@ -354,16 +354,82 @@ public:
 private:
   WebMBufferedParser mParser;
   nsTArray<WebMTimeDataOffset> mOverlappedMapping;
   int64_t mOffset;
   Maybe<WebMTimeDataOffset> mLastMapping;
 };
 
 #ifdef MOZ_FMP4
+
+class MP4Stream : public mp4_demuxer::Stream
+{
+public:
+  explicit MP4Stream(MediaResource* aResource);
+  virtual ~MP4Stream();
+  bool ReadAt(int64_t aOffset,
+              void* aBuffer,
+              size_t aCount,
+              size_t* aBytesRead) override;
+  bool CachedReadAt(int64_t aOffset,
+                    void* aBuffer,
+                    size_t aCount,
+                    size_t* aBytesRead) override;
+  bool Length(int64_t* aSize) override;
+
+private:
+  MediaResourceIndex mResource;
+};
+
+MP4Stream::MP4Stream(MediaResource* aResource)
+  : mResource(aResource)
+{
+  MOZ_COUNT_CTOR(MP4Stream);
+  MOZ_ASSERT(aResource);
+}
+
+MP4Stream::~MP4Stream()
+{
+  MOZ_COUNT_DTOR(MP4Stream);
+}
+
+bool
+MP4Stream::ReadAt(int64_t aOffset,
+                  void* aBuffer,
+                  size_t aCount,
+                  size_t* aBytesRead)
+{
+  return CachedReadAt(aOffset, aBuffer, aCount, aBytesRead);
+}
+
+bool
+MP4Stream::CachedReadAt(int64_t aOffset,
+                        void* aBuffer,
+                        size_t aCount,
+                        size_t* aBytesRead)
+{
+  nsresult rv = mResource.GetResource()->ReadFromCache(
+    reinterpret_cast<char*>(aBuffer), aOffset, aCount);
+  if (NS_FAILED(rv)) {
+    *aBytesRead = 0;
+    return false;
+  }
+  *aBytesRead = aCount;
+  return true;
+}
+
+bool
+MP4Stream::Length(int64_t* aSize)
+{
+  if (mResource.GetLength() < 0)
+    return false;
+  *aSize = mResource.GetLength();
+  return true;
+}
+
 class MP4ContainerParser : public ContainerParser
 {
 public:
   explicit MP4ContainerParser(const MediaContainerType& aType)
     : ContainerParser(aType)
   {
   }