diff --git a/content/html/content/public/nsHTMLMediaElement.h b/content/html/content/public/nsHTMLMediaElement.h
index c02b45f91158..a2d0fe57e8e8 100644
--- a/content/html/content/public/nsHTMLMediaElement.h
+++ b/content/html/content/public/nsHTMLMediaElement.h
@@ -16,7 +16,6 @@
 #include "nsCycleCollectionParticipant.h"
 #include "nsILoadGroup.h"
 #include "nsIObserver.h"
-#include "nsDataHashtable.h"
 #include "nsAudioStream.h"
 #include "VideoFrameContainer.h"
 #include "mozilla/CORSMode.h"
@@ -47,8 +46,6 @@ public:
   typedef mozilla::MediaStream MediaStream;
   typedef mozilla::MediaResource MediaResource;
 
-  typedef nsDataHashtable<nsCStringHashKey, nsCString> MetadataTags;
-
 #ifdef MOZ_DASH
   friend class nsDASHDecoder;
 #endif
diff --git a/content/media/dash/nsDASHReader.cpp b/content/media/dash/nsDASHReader.cpp
index be589acc4abe..94fe7413ea2b 100644
--- a/content/media/dash/nsDASHReader.cpp
+++ b/content/media/dash/nsDASHReader.cpp
@@ -114,7 +114,7 @@ nsDASHReader::DecodeAudioData()
 
 nsresult
 nsDASHReader::ReadMetadata(nsVideoInfo* aInfo,
-                           nsHTMLMediaElement::MetadataTags** aTags)
+                           MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/dash/nsDASHReader.h b/content/media/dash/nsDASHReader.h
index 0948647ebe89..302cd706450f 100644
--- a/content/media/dash/nsDASHReader.h
+++ b/content/media/dash/nsDASHReader.h
@@ -48,7 +48,7 @@ public:
   // Waits for metadata bytes to be downloaded, then reads and parses them.
   // Called on the decode thread only.
   nsresult ReadMetadata(nsVideoInfo* aInfo,
-                        nsHTMLMediaElement::MetadataTags** aTags);
+                        MetadataTags** aTags);
 
   // Waits for |ReadyToReadMetadata| or |NotifyDecoderShuttingDown|
   // notification, whichever comes first. Ensures no attempt to read metadata
diff --git a/content/media/gstreamer/nsGStreamerReader.cpp b/content/media/gstreamer/nsGStreamerReader.cpp
index cdabbd4d9235..c9602cf3380b 100644
--- a/content/media/gstreamer/nsGStreamerReader.cpp
+++ b/content/media/gstreamer/nsGStreamerReader.cpp
@@ -195,7 +195,7 @@ void nsGStreamerReader::PlayBinSourceSetup(GstAppSrc *aSource)
 }
 
 nsresult nsGStreamerReader::ReadMetadata(nsVideoInfo* aInfo,
-                                         nsHTMLMediaElement::MetadataTags** aTags)
+                                         MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
   nsresult ret = NS_OK;
diff --git a/content/media/gstreamer/nsGStreamerReader.h b/content/media/gstreamer/nsGStreamerReader.h
index b7a929ff6767..1a616be6e53f 100644
--- a/content/media/gstreamer/nsGStreamerReader.h
+++ b/content/media/gstreamer/nsGStreamerReader.h
@@ -27,7 +27,7 @@ public:
   virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
                                 int64_t aTimeThreshold);
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime,
                         int64_t aStartTime,
                         int64_t aEndTime,
diff --git a/content/media/nsBuiltinDecoder.cpp b/content/media/nsBuiltinDecoder.cpp
index 20d08e8802f7..90b26baa7a6d 100644
--- a/content/media/nsBuiltinDecoder.cpp
+++ b/content/media/nsBuiltinDecoder.cpp
@@ -543,7 +543,7 @@ void nsBuiltinDecoder::AudioAvailable(float* aFrameBuffer,
 void nsBuiltinDecoder::MetadataLoaded(uint32_t aChannels,
                                       uint32_t aRate,
                                       bool aHasAudio,
-                                      const nsHTMLMediaElement::MetadataTags* aTags)
+                                      const MetadataTags* aTags)
 {
   NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
   if (mShuttingDown) {
diff --git a/content/media/nsBuiltinDecoder.h b/content/media/nsBuiltinDecoder.h
index 3407c962b46f..ee6353af7466 100644
--- a/content/media/nsBuiltinDecoder.h
+++ b/content/media/nsBuiltinDecoder.h
@@ -506,7 +506,7 @@ public:
   void MetadataLoaded(uint32_t aChannels,
                       uint32_t aRate,
                       bool aHasAudio,
-                      const nsHTMLMediaElement::MetadataTags* aTags);
+                      const MetadataTags* aTags);
 
   // Called when the first frame has been loaded.
   // Call on the main thread only.
diff --git a/content/media/nsBuiltinDecoderReader.h b/content/media/nsBuiltinDecoderReader.h
index 469448490bfd..7ee69ffebe01 100644
--- a/content/media/nsBuiltinDecoderReader.h
+++ b/content/media/nsBuiltinDecoderReader.h
@@ -395,7 +395,7 @@ public:
   // with tag metadata from the file.
   // Returns NS_OK on success, or NS_ERROR_FAILURE on failure.
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags) = 0;
+                                MetadataTags** aTags) = 0;
 
   // Stores the presentation time of the first frame we'd be able to play if
   // we started playback at the current position. Returns the first video
diff --git a/content/media/nsBuiltinDecoderStateMachine.cpp b/content/media/nsBuiltinDecoderStateMachine.cpp
index ec03d2c36219..9fda48305e0e 100644
--- a/content/media/nsBuiltinDecoderStateMachine.cpp
+++ b/content/media/nsBuiltinDecoderStateMachine.cpp
@@ -118,7 +118,7 @@ private:
 public:
   nsAudioMetadataEventRunner(nsBuiltinDecoder* aDecoder, uint32_t aChannels,
                              uint32_t aRate, bool aHasAudio,
-                             nsHTMLMediaElement::MetadataTags* aTags) :
+                             MetadataTags* aTags) :
     mDecoder(aDecoder),
     mChannels(aChannels),
     mRate(aRate),
@@ -136,7 +136,7 @@ public:
   const uint32_t mChannels;
   const uint32_t mRate;
   const bool mHasAudio;
-  nsHTMLMediaElement::MetadataTags* mTags;
+  MetadataTags* mTags;
 };
 
 // Owns the global state machine thread and counts of
@@ -1726,7 +1726,7 @@ nsresult nsBuiltinDecoderStateMachine::DecodeMetadata()
   LOG(PR_LOG_DEBUG, ("%p Decoding Media Headers", mDecoder.get()));
   nsresult res;
   nsVideoInfo info;
-  nsHTMLMediaElement::MetadataTags* tags;
+  MetadataTags* tags;
   {
     ReentrantMonitorAutoExit exitMon(mDecoder->GetReentrantMonitor());
     res = mReader->ReadMetadata(&info, &tags);
diff --git a/content/media/nsMediaDecoder.h b/content/media/nsMediaDecoder.h
index 7a442735cd3c..299437ab97f1 100644
--- a/content/media/nsMediaDecoder.h
+++ b/content/media/nsMediaDecoder.h
@@ -10,6 +10,7 @@
 #include "VideoFrameContainer.h"
 #include "MediaStreamGraph.h"
 #include "nsIObserver.h"
+#include "nsDataHashtable.h"
 
 class nsHTMLMediaElement;
 class nsIStreamListener;
@@ -33,6 +34,8 @@ static const uint32_t FRAMEBUFFER_LENGTH_PER_CHANNEL = 1024;
 static const uint32_t FRAMEBUFFER_LENGTH_MIN = 512;
 static const uint32_t FRAMEBUFFER_LENGTH_MAX = 16384;
 
+typedef nsDataHashtable<nsCStringHashKey, nsCString> MetadataTags;
+
 // All methods of nsMediaDecoder must be called from the main thread only
 // with the exception of GetVideoFrameContainer and GetStatistics,
 // which can be called from any thread.
diff --git a/content/media/ogg/nsOggCodecState.cpp b/content/media/ogg/nsOggCodecState.cpp
index 0cf3a25389b8..512e4f9a0594 100644
--- a/content/media/ogg/nsOggCodecState.cpp
+++ b/content/media/ogg/nsOggCodecState.cpp
@@ -130,7 +130,7 @@ bool nsOggCodecState::IsValidVorbisTagName(nsCString& aName)
   return true;
 }
 
-bool nsOggCodecState::AddVorbisComment(nsHTMLMediaElement::MetadataTags* aTags,
+bool nsOggCodecState::AddVorbisComment(MetadataTags* aTags,
                                        const char* aComment,
                                        uint32_t aLength)
 {
@@ -654,13 +654,13 @@ nsVorbisState::IsHeader(ogg_packet* aPacket)
   return aPacket->bytes > 0 ? (aPacket->packet[0] & 0x1) : false;
 }
 
-nsHTMLMediaElement::MetadataTags*
+MetadataTags*
 nsVorbisState::GetTags()
 {
-  nsHTMLMediaElement::MetadataTags* tags;
+  MetadataTags* tags;
   NS_ASSERTION(mComment.user_comments, "no vorbis comment strings!");
   NS_ASSERTION(mComment.comment_lengths, "no vorbis comment lengths!");
-  tags = new nsHTMLMediaElement::MetadataTags;
+  tags = new MetadataTags;
   tags->Init();
   for (int i = 0; i < mComment.comments; i++) {
     AddVorbisComment(tags, mComment.user_comments[i],
@@ -1037,11 +1037,11 @@ bool nsOpusState::DecodeHeader(ogg_packet* aPacket)
 }
 
 /* Construct and return a tags hashmap from our internal array */
-nsHTMLMediaElement::MetadataTags* nsOpusState::GetTags()
+MetadataTags* nsOpusState::GetTags()
 {
-  nsHTMLMediaElement::MetadataTags* tags;
+  MetadataTags* tags;
 
-  tags = new nsHTMLMediaElement::MetadataTags;
+  tags = new MetadataTags;
   tags->Init();
   for (uint32_t i = 0; i < mTags.Length(); i++) {
     AddVorbisComment(tags, mTags[i].Data(), mTags[i].Length());
diff --git a/content/media/ogg/nsOggCodecState.h b/content/media/ogg/nsOggCodecState.h
index ce4899d272d8..aaef07d9daad 100644
--- a/content/media/ogg/nsOggCodecState.h
+++ b/content/media/ogg/nsOggCodecState.h
@@ -98,7 +98,7 @@ public:
   }
 
   // Build a hash table with tag metadata parsed from the stream.
-  virtual nsHTMLMediaElement::MetadataTags* GetTags() {
+  virtual MetadataTags* GetTags() {
     return nullptr;
   }
 
@@ -200,7 +200,7 @@ protected:
   // Utility method to parse and add a vorbis-style comment
   // to a metadata hash table. Most Ogg-encapsulated codecs
   // use the vorbis comment format for metadata.
-  static bool AddVorbisComment(nsHTMLMediaElement::MetadataTags* aTags,
+  static bool AddVorbisComment(MetadataTags* aTags,
                         const char* aComment,
                         uint32_t aLength);
 };
@@ -219,7 +219,7 @@ public:
   nsresult PageIn(ogg_page* aPage); 
 
   // Return a hash table with tag metadata.
-  nsHTMLMediaElement::MetadataTags* GetTags();
+  MetadataTags* GetTags();
 
   // Returns the end time that a granulepos represents.
   static int64_t Time(vorbis_info* aInfo, int64_t aGranulePos); 
@@ -357,7 +357,7 @@ public:
   int64_t mPrevPacketGranulepos;
 
   // Construct and return a table of tags from the metadata header.
-  nsHTMLMediaElement::MetadataTags* GetTags();
+  MetadataTags* GetTags();
 
 private:
 
diff --git a/content/media/ogg/nsOggReader.cpp b/content/media/ogg/nsOggReader.cpp
index a5c97c6d9337..3925b7f37e6d 100644
--- a/content/media/ogg/nsOggReader.cpp
+++ b/content/media/ogg/nsOggReader.cpp
@@ -162,7 +162,7 @@ void nsOggReader::BuildSerialList(nsTArray<uint32_t>& aTracks)
 }
 
 nsresult nsOggReader::ReadMetadata(nsVideoInfo* aInfo,
-                                   nsHTMLMediaElement::MetadataTags** aTags)
+                                   MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/ogg/nsOggReader.h b/content/media/ogg/nsOggReader.h
index 71504547560e..7daba169720f 100644
--- a/content/media/ogg/nsOggReader.h
+++ b/content/media/ogg/nsOggReader.h
@@ -47,7 +47,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
 
diff --git a/content/media/omx/nsMediaOmxReader.cpp b/content/media/omx/nsMediaOmxReader.cpp
index d31bbcdb6d41..bfb90474ca2b 100644
--- a/content/media/omx/nsMediaOmxReader.cpp
+++ b/content/media/omx/nsMediaOmxReader.cpp
@@ -38,7 +38,7 @@ nsresult nsMediaOmxReader::Init(nsBuiltinDecoderReader* aCloneDonor)
 }
 
 nsresult nsMediaOmxReader::ReadMetadata(nsVideoInfo* aInfo,
-                                        nsHTMLMediaElement::MetadataTags** aTags)
+                                        MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/omx/nsMediaOmxReader.h b/content/media/omx/nsMediaOmxReader.h
index 1a2dd199604e..d33b2650da88 100644
--- a/content/media/omx/nsMediaOmxReader.h
+++ b/content/media/omx/nsMediaOmxReader.h
@@ -47,7 +47,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
   virtual bool IsSeekableInBufferedRanges() {
diff --git a/content/media/plugins/nsMediaPluginReader.cpp b/content/media/plugins/nsMediaPluginReader.cpp
index 86660fcacb60..4252587f41aa 100644
--- a/content/media/plugins/nsMediaPluginReader.cpp
+++ b/content/media/plugins/nsMediaPluginReader.cpp
@@ -37,7 +37,7 @@ nsresult nsMediaPluginReader::Init(nsBuiltinDecoderReader* aCloneDonor)
 }
 
 nsresult nsMediaPluginReader::ReadMetadata(nsVideoInfo* aInfo,
-                                           nsHTMLMediaElement::MetadataTags** aTags)
+                                           MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/plugins/nsMediaPluginReader.h b/content/media/plugins/nsMediaPluginReader.h
index aaa6ee27fc92..2fe05c2b068c 100644
--- a/content/media/plugins/nsMediaPluginReader.h
+++ b/content/media/plugins/nsMediaPluginReader.h
@@ -45,7 +45,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
   virtual bool IsSeekableInBufferedRanges() {
diff --git a/content/media/raw/nsRawReader.cpp b/content/media/raw/nsRawReader.cpp
index 37adf23064a0..77bce16710fb 100644
--- a/content/media/raw/nsRawReader.cpp
+++ b/content/media/raw/nsRawReader.cpp
@@ -35,7 +35,7 @@ nsresult nsRawReader::ResetDecode()
 }
 
 nsresult nsRawReader::ReadMetadata(nsVideoInfo* aInfo,
-                                   nsHTMLMediaElement::MetadataTags** aTags)
+                                   MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(),
                "Should be on decode thread.");
diff --git a/content/media/raw/nsRawReader.h b/content/media/raw/nsRawReader.h
index 254fa12eefce..d3696abd4b5f 100644
--- a/content/media/raw/nsRawReader.h
+++ b/content/media/raw/nsRawReader.h
@@ -33,7 +33,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
 
diff --git a/content/media/wave/nsWaveReader.cpp b/content/media/wave/nsWaveReader.cpp
index bbcb09fe3db8..c7e2db670114 100644
--- a/content/media/wave/nsWaveReader.cpp
+++ b/content/media/wave/nsWaveReader.cpp
@@ -121,7 +121,7 @@ nsresult nsWaveReader::Init(nsBuiltinDecoderReader* aCloneDonor)
 }
 
 nsresult nsWaveReader::ReadMetadata(nsVideoInfo* aInfo,
-                                    nsHTMLMediaElement::MetadataTags** aTags)
+                                    MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/wave/nsWaveReader.h b/content/media/wave/nsWaveReader.h
index 690dcfe5a264..d00ec5b33e41 100644
--- a/content/media/wave/nsWaveReader.h
+++ b/content/media/wave/nsWaveReader.h
@@ -33,7 +33,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
 
diff --git a/content/media/webm/nsWebMReader.cpp b/content/media/webm/nsWebMReader.cpp
index ca0069cd80a6..989da7b8bb00 100644
--- a/content/media/webm/nsWebMReader.cpp
+++ b/content/media/webm/nsWebMReader.cpp
@@ -180,7 +180,7 @@ void nsWebMReader::Cleanup()
 }
 
 nsresult nsWebMReader::ReadMetadata(nsVideoInfo* aInfo,
-                                    nsHTMLMediaElement::MetadataTags** aTags)
+                                    MetadataTags** aTags)
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
 
diff --git a/content/media/webm/nsWebMReader.h b/content/media/webm/nsWebMReader.h
index 47007e5175fa..cd3ed4822d12 100644
--- a/content/media/webm/nsWebMReader.h
+++ b/content/media/webm/nsWebMReader.h
@@ -131,7 +131,7 @@ public:
   }
 
   virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
-                                nsHTMLMediaElement::MetadataTags** aTags);
+                                MetadataTags** aTags);
   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
   virtual nsresult GetBuffered(nsTimeRanges* aBuffered, int64_t aStartTime);
   virtual void NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset);