diff --git a/dom/media/ChannelMediaDecoder.cpp b/dom/media/ChannelMediaDecoder.cpp
index 9a8a4aff8990..6d2e2831fed0 100644
--- a/dom/media/ChannelMediaDecoder.cpp
+++ b/dom/media/ChannelMediaDecoder.cpp
@@ -201,6 +201,7 @@ MediaDecoderStateMachine* ChannelMediaDecoder::CreateStateMachine()
   init.mCrashHelper = GetOwner()->CreateGMPCrashHelper();
   init.mFrameStats = mFrameStats;
   init.mResource = mResource;
+  init.mMediaDecoderOwnerID = mOwner;
   mReader = DecoderTraits::CreateReader(ContainerType(), init);
   return new MediaDecoderStateMachine(this, mReader);
 }
diff --git a/dom/media/MediaFormatReader.cpp b/dom/media/MediaFormatReader.cpp
index 40875d0e59e1..ed0eb82396bb 100644
--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -1114,6 +1114,7 @@ MediaFormatReader::MediaFormatReader(MediaFormatReaderInit& aInit,
               TimeIntervals(),
               "MediaFormatReader::mBuffered (Canonical)")
   , mFrameStats(aInit.mFrameStats)
+  , mMediaDecoderOwnerID(aInit.mMediaDecoderOwnerID)
 {
   MOZ_ASSERT(aDemuxer);
   MOZ_COUNT_CTOR(MediaFormatReader);
diff --git a/dom/media/MediaFormatReader.h b/dom/media/MediaFormatReader.h
index 510c231607ba..1e3f635958c5 100644
--- a/dom/media/MediaFormatReader.h
+++ b/dom/media/MediaFormatReader.h
@@ -73,6 +73,8 @@ struct MetadataHolder
   UniquePtr<MetadataTags> mTags;
 };
 
+typedef void* MediaDecoderOwnerID;
+
 struct MOZ_STACK_CLASS MediaFormatReaderInit
 {
   MediaResource* mResource = nullptr;
@@ -80,6 +82,8 @@ struct MOZ_STACK_CLASS MediaFormatReaderInit
   FrameStatistics* mFrameStats = nullptr;
   already_AddRefed<layers::KnowsCompositor> mKnowsCompositor;
   already_AddRefed<GMPCrashHelper> mCrashHelper;
+  // Used in bug 1393399 for temporary telemetry.
+  MediaDecoderOwnerID mMediaDecoderOwnerID = nullptr;
 };
 
 class MediaFormatReader final
@@ -762,6 +766,9 @@ private:
   MediaEventProducer<MediaResult> mOnDecodeWarning;
 
   RefPtr<FrameStatistics> mFrameStats;
+
+  // Used in bug 1393399 for telemetry.
+  const MediaDecoderOwnerID mMediaDecoderOwnerID;
 };
 
 } // namespace mozilla
diff --git a/dom/media/hls/HLSDecoder.cpp b/dom/media/hls/HLSDecoder.cpp
index 6d5bc5ca973c..0fc67db0e262 100644
--- a/dom/media/hls/HLSDecoder.cpp
+++ b/dom/media/hls/HLSDecoder.cpp
@@ -93,6 +93,7 @@ HLSDecoder::CreateStateMachine()
   init.mKnowsCompositor = GetCompositor();
   init.mCrashHelper = GetOwner()->CreateGMPCrashHelper();
   init.mFrameStats = mFrameStats;
+  init.mMediaDecoderOwnerID = mOwner;
   mReader =
     new MediaFormatReader(init, new HLSDemuxer(mHLSResourceWrapper->GetPlayerId()));
 
diff --git a/dom/media/mediasource/MediaSourceDecoder.cpp b/dom/media/mediasource/MediaSourceDecoder.cpp
index af0aa4f5f39e..f6849032937f 100644
--- a/dom/media/mediasource/MediaSourceDecoder.cpp
+++ b/dom/media/mediasource/MediaSourceDecoder.cpp
@@ -42,6 +42,7 @@ MediaSourceDecoder::CreateStateMachine()
   init.mKnowsCompositor = GetCompositor();
   init.mCrashHelper = GetOwner()->CreateGMPCrashHelper();
   init.mFrameStats = mFrameStats;
+  init.mMediaDecoderOwnerID = mOwner;
   mReader = new MediaFormatReader(init, mDemuxer);
   return new MediaDecoderStateMachine(this, mReader);
 }