diff --git a/dom/media/gtest/TestMP4Demuxer.cpp b/dom/media/gtest/TestMP4Demuxer.cpp
index 5f43136c2bef..b756e8a4dd73 100644
--- a/dom/media/gtest/TestMP4Demuxer.cpp
+++ b/dom/media/gtest/TestMP4Demuxer.cpp
@@ -4,32 +4,151 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "gtest/gtest.h"
-#include "mp4_demuxer/mp4_demuxer.h"
+#include "MP4Demuxer.h"
 #include "MP4Stream.h"
+#include "MozPromise.h"
+#include "MediaDataDemuxer.h"
+#include "SharedThreadPool.h"
+#include "TaskQueue.h"
 #include "mozilla/ArrayUtils.h"
 #include "MockMediaResource.h"
 
 using namespace mozilla;
 using namespace mp4_demuxer;
 
+class AutoTaskQueue;
+
+#define DO_FAIL []()->void { EXPECT_TRUE(false); }
+
 class MP4DemuxerBinding
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MP4DemuxerBinding);
 
   nsRefPtr<MockMediaResource> resource;
-  Monitor mMonitor;
-  nsRefPtr<MP4Demuxer> demuxer;
+  nsRefPtr<MP4Demuxer> mDemuxer;
+  nsRefPtr<TaskQueue> mTaskQueue;
+  nsRefPtr<MediaTrackDemuxer> mAudioTrack;
+  nsRefPtr<MediaTrackDemuxer> mVideoTrack;
+  uint32_t mIndex;
+  nsTArray<nsRefPtr<MediaRawData>> mSamples;
+  nsTArray<int64_t> mKeyFrameTimecodes;
+  MozPromiseHolder<GenericPromise> mCheckTrackKeyFramePromise;
+  MozPromiseHolder<GenericPromise> mCheckTrackSamples;
 
   explicit MP4DemuxerBinding(const char* aFileName = "dash_dashinit.mp4")
     : resource(new MockMediaResource(aFileName))
-    , mMonitor("TestMP4Demuxer monitor")
-    , demuxer(new MP4Demuxer(new MP4Stream(resource), &mMonitor))
+    , mDemuxer(new MP4Demuxer(resource))
+    , mTaskQueue(new TaskQueue(GetMediaThreadPool(MediaThreadType::PLAYBACK)))
+    , mIndex(0)
   {
     EXPECT_EQ(NS_OK, resource->Open(nullptr));
   }
 
+  template<typename Function>
+  void RunTestAndWait(const Function& aFunction)
+  {
+    Function func(aFunction);
+    mDemuxer->Init()->Then(mTaskQueue, __func__, Move(func), DO_FAIL);
+    mTaskQueue->AwaitShutdownAndIdle();
+  }
+
+  nsRefPtr<GenericPromise>
+  CheckTrackKeyFrame(MediaTrackDemuxer* aTrackDemuxer)
+  {
+    MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+
+    nsRefPtr<MediaTrackDemuxer> track = aTrackDemuxer;
+    nsRefPtr<MP4DemuxerBinding> self = this;
+
+    int64_t time = -1;
+    while (mIndex < mSamples.Length()) {
+      uint32_t i = mIndex++;
+      if (mSamples[i]->mKeyframe) {
+        time = mSamples[i]->mTime;
+        break;
+      }
+    }
+
+    nsRefPtr<GenericPromise> p = mCheckTrackKeyFramePromise.Ensure(__func__);
+
+    if (time == -1) {
+      mCheckTrackKeyFramePromise.Resolve(true, __func__);
+      return p;
+    }
+
+
+    DispatchTask(
+      [track, time, self] () {
+        track->Seek(media::TimeUnit::FromMicroseconds(time))->Then(self->mTaskQueue, __func__,
+          [track, time, self] () {
+            track->GetSamples()->Then(self->mTaskQueue, __func__,
+              [track, time, self] (nsRefPtr<MediaTrackDemuxer::SamplesHolder> aSamples) {
+                EXPECT_EQ(time, aSamples->mSamples[0]->mTime);
+                self->CheckTrackKeyFrame(track);
+              },
+              DO_FAIL
+            );
+          },
+          DO_FAIL
+        );
+      }
+    );
+
+    return p;
+  }
+
+  nsRefPtr<GenericPromise>
+  CheckTrackSamples(MediaTrackDemuxer* aTrackDemuxer)
+  {
+    MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+
+    nsRefPtr<MediaTrackDemuxer> track = aTrackDemuxer;
+    nsRefPtr<MP4DemuxerBinding> self = this;
+
+    nsRefPtr<GenericPromise> p = mCheckTrackSamples.Ensure(__func__);
+
+    DispatchTask(
+      [track, self] () {
+        track->GetSamples()->Then(self->mTaskQueue, __func__,
+          [track, self] (nsRefPtr<MediaTrackDemuxer::SamplesHolder> aSamples) {
+            if (aSamples->mSamples.Length()) {
+              self->mSamples.AppendElements(aSamples->mSamples);
+              self->CheckTrackSamples(track);
+            }
+          },
+          [self] (DemuxerFailureReason aReason) {
+            if (aReason == DemuxerFailureReason::DEMUXER_ERROR) {
+              EXPECT_TRUE(false);
+              self->mCheckTrackSamples.Reject(NS_ERROR_FAILURE, __func__);
+            } else if (aReason == DemuxerFailureReason::END_OF_STREAM) {
+              EXPECT_TRUE(self->mSamples.Length() > 1);
+              for (uint32_t i = 0; i < (self->mSamples.Length() - 1); i++) {
+                EXPECT_LT(self->mSamples[i]->mTimecode, self->mSamples[i + 1]->mTimecode);
+                if (self->mSamples[i]->mKeyframe) {
+                  self->mKeyFrameTimecodes.AppendElement(self->mSamples[i]->mTimecode);
+                }
+              }
+              self->mCheckTrackSamples.Resolve(true, __func__);
+            }
+          }
+        );
+      }
+    );
+
+    return p;
+  }
+
 private:
+
+  template<typename FunctionType>
+  void
+  DispatchTask(FunctionType aFun)
+  {
+    nsRefPtr<nsRunnable> r = NS_NewRunnableFunction(aFun);
+    mTaskQueue->Dispatch(r.forget());
+  }
+
   virtual ~MP4DemuxerBinding()
   {
   }
@@ -37,30 +156,20 @@ private:
 
 TEST(MP4Demuxer, Seek)
 {
-  nsRefPtr<MP4DemuxerBinding> b = new MP4DemuxerBinding();
-  MonitorAutoLock mon(b->mMonitor);
-  MP4Demuxer* d = b->demuxer;
+  nsRefPtr<MP4DemuxerBinding> binding = new MP4DemuxerBinding();
 
-  EXPECT_TRUE(d->Init());
-
-  nsTArray<nsRefPtr<MediaRawData>> samples;
-  nsRefPtr<MediaRawData> sample;
-  while (!!(sample = d->DemuxVideoSample())) {
-    samples.AppendElement(sample);
-    if (samples.Length() >= 2) {
-      EXPECT_LT(samples[samples.Length() - 2]->mTimecode,
-                samples[samples.Length() - 1]->mTimecode);
-    }
-  }
-  Microseconds keyFrame = 0;
-  for (size_t i = 0; i < samples.Length(); i++) {
-    if (samples[i]->mKeyframe) {
-      keyFrame = samples[i]->mTimecode;
-    }
-    d->SeekVideo(samples[i]->mTime);
-    sample = d->DemuxVideoSample();
-    EXPECT_EQ(keyFrame, sample->mTimecode);
-  }
+  binding->RunTestAndWait([binding] () {
+    binding->mVideoTrack = binding->mDemuxer->GetTrackDemuxer(TrackInfo::kVideoTrack, 0);
+    binding->CheckTrackSamples(binding->mVideoTrack)
+      ->Then(binding->mTaskQueue, __func__,
+        [binding] () {
+          binding->CheckTrackKeyFrame(binding->mVideoTrack)
+            ->Then(binding->mTaskQueue, __func__,
+              [binding] () {
+                binding->mTaskQueue->BeginShutdown();
+              }, DO_FAIL);
+        }, DO_FAIL);
+  });
 }
 
 static nsCString
@@ -87,14 +196,10 @@ ToCryptoString(const CryptoSample& aCrypto)
   return res;
 }
 
+#ifndef XP_WIN // VC2013 doesn't support C++11 array initialization.
+
 TEST(MP4Demuxer, CENCFrag)
 {
-  nsRefPtr<MP4DemuxerBinding> b = new MP4DemuxerBinding("gizmo-frag.mp4");
-  MonitorAutoLock mon(b->mMonitor);
-  MP4Demuxer* d = b->demuxer;
-
-  EXPECT_TRUE(d->Init());
-
   const char* video[] = {
     "1 16 7e571d037e571d037e571d037e571d03 00000000000000000000000000000000 5,684 5,16980",
     "1 16 7e571d037e571d037e571d037e571d03 00000000000000000000000000000450 5,1826",
@@ -158,13 +263,22 @@ TEST(MP4Demuxer, CENCFrag)
     "1 16 7e571d037e571d037e571d037e571d03 000000000000000000000000000019cd 5,2392",
   };
 
-  nsRefPtr<MediaRawData> sample;
-  size_t i = 0;
-  while (!!(sample = d->DemuxVideoSample())) {
-    nsCString text = ToCryptoString(sample->mCrypto);
-    EXPECT_STREQ(video[i++], text.get());
-  }
-  EXPECT_EQ(ArrayLength(video), i);
+  nsRefPtr<MP4DemuxerBinding> binding = new MP4DemuxerBinding("gizmo-frag.mp4");
+
+  binding->RunTestAndWait([binding, video] () {
+    // grab all video samples.
+    binding->mVideoTrack = binding->mDemuxer->GetTrackDemuxer(TrackInfo::kVideoTrack, 0);
+    binding->CheckTrackSamples(binding->mVideoTrack)
+      ->Then(binding->mTaskQueue, __func__,
+        [binding, video] () {
+          for (uint32_t i = 0; i < binding->mSamples.Length(); i++) {
+            nsCString text = ToCryptoString(binding->mSamples[i]->mCrypto);
+            EXPECT_STREQ(video[i++], text.get());
+          }
+          EXPECT_EQ(ArrayLength(video), binding->mSamples.Length());
+          binding->mTaskQueue->BeginShutdown();
+        }, DO_FAIL);
+  });
 
   const char* audio[] = {
     "1 16 7e571d047e571d047e571d047e571d04 00000000000000000000000000000000 0,281",
@@ -262,42 +376,52 @@ TEST(MP4Demuxer, CENCFrag)
     "1 16 7e571d047e571d047e571d047e571d04 000000000000000000000000000008cd 0,433",
     "1 16 7e571d047e571d047e571d047e571d04 000000000000000000000000000008e9 0,481",
   };
+  nsRefPtr<MP4DemuxerBinding> audiobinding = new MP4DemuxerBinding("gizmo-frag.mp4");
 
-  i = 0;
-  while (!!(sample = d->DemuxAudioSample())) {
-    nsCString text = ToCryptoString(sample->mCrypto);
-    EXPECT_STREQ(audio[i++], text.get());
-  }
-  EXPECT_EQ(ArrayLength(audio), i);
+  audiobinding->RunTestAndWait([audiobinding, audio] () {
+    // grab all audio samples.
+    audiobinding->mAudioTrack = audiobinding->mDemuxer->GetTrackDemuxer(TrackInfo::kAudioTrack, 0);
+    audiobinding->CheckTrackSamples(audiobinding->mAudioTrack)
+      ->Then(audiobinding->mTaskQueue, __func__,
+        [audiobinding, audio] () {
+          EXPECT_TRUE(audiobinding->mSamples.Length() > 1);
+          for (uint32_t i = 0; i < audiobinding->mSamples.Length(); i++) {
+            nsCString text = ToCryptoString(audiobinding->mSamples[i]->mCrypto);
+            EXPECT_STREQ(audio[i++], text.get());
+          }
+          EXPECT_EQ(ArrayLength(audio), audiobinding->mSamples.Length());
+          audiobinding->mTaskQueue->BeginShutdown();
+        }, DO_FAIL);
+  });
 }
 
+#endif
+
 TEST(MP4Demuxer, GetNextKeyframe)
 {
-  nsRefPtr<MP4DemuxerBinding> b = new MP4DemuxerBinding("gizmo-frag.mp4");
-  MonitorAutoLock mon(b->mMonitor);
-  MP4Demuxer* d = b->demuxer;
+  nsRefPtr<MP4DemuxerBinding> binding = new MP4DemuxerBinding("gizmo-frag.mp4");
 
-  EXPECT_TRUE(d->Init());
+  binding->RunTestAndWait([binding] () {
+    // Insert a [0,end] buffered range, to simulate Moof's being buffered
+    // via MSE.
+    auto len = binding->resource->GetLength();
+    binding->resource->MockAddBufferedRange(0, len);
 
-  // Insert a [0,end] buffered range, to simulate Moof's being buffered
-  // via MSE.
-  auto len = b->resource->GetLength();
-  b->resource->MockAddBufferedRange(0, len);
-
-  // Rebuild the index so that it can be used to find the keyframes.
-  nsTArray<MediaByteRange> ranges;
-  EXPECT_TRUE(NS_SUCCEEDED(b->resource->GetCachedRanges(ranges)));
-  d->UpdateIndex(ranges);
-
-  // gizmp-frag has two keyframes; one at dts=cts=0, and another at
-  // dts=cts=1000000. Verify we get expected results.
-
-  nsRefPtr<MediaRawData> sample;
-  size_t i = 0;
-  const int64_t keyframe = 1000000;
-  while (!!(sample = d->DemuxVideoSample())) {
-    int64_t expected = (sample->mTimecode < keyframe) ? keyframe : -1;
-    EXPECT_EQ(d->GetNextKeyframeTime(), expected);
-    i++;
-  }
+    // gizmp-frag has two keyframes; one at dts=cts=0, and another at
+    // dts=cts=1000000. Verify we get expected results.
+    media::TimeUnit time;
+    binding->mVideoTrack = binding->mDemuxer->GetTrackDemuxer(TrackInfo::kVideoTrack, 0);
+    binding->mVideoTrack->Reset();
+    binding->mVideoTrack->GetNextRandomAccessPoint(&time);
+    EXPECT_EQ(time.ToMicroseconds(), 0);
+    binding->mVideoTrack->GetSamples()->Then(binding->mTaskQueue, __func__,
+      [binding] () {
+        media::TimeUnit time;
+        binding->mVideoTrack->GetNextRandomAccessPoint(&time);
+        EXPECT_EQ(time.ToMicroseconds(), 1000000);
+        binding->mTaskQueue->BeginShutdown();
+      },
+      DO_FAIL
+    );
+  });
 }
diff --git a/dom/media/gtest/moz.build b/dom/media/gtest/moz.build
index 8cb5223d8bfc..2e8db6947801 100644
--- a/dom/media/gtest/moz.build
+++ b/dom/media/gtest/moz.build
@@ -12,6 +12,7 @@ UNIFIED_SOURCES += [
     'TestIntervalSet.cpp',
     'TestMozPromise.cpp',
     'TestMP3Demuxer.cpp',
+    'TestMP4Demuxer.cpp',
     # 'TestMP4Reader.cpp', disabled so we can turn check tests back on (bug 1175752)
     'TestTrackEncoder.cpp',
     'TestVideoSegment.cpp',