--- a/dom/media/BaseMediaResource.h
+++ b/dom/media/BaseMediaResource.h
@@ -59,17 +59,17 @@ public:
   // since we don't expect to resume again any time soon. Otherwise we
   // may resume again soon so resources should be held for a little
   // while.
   virtual void Suspend(bool aCloseImmediately) = 0;
 
   // Resume any downloads that have been suspended.
   virtual void Resume() = 0;
 
-  // The mode is initially MODE_PLAYBACK.
+  // The mode is initially MODE_METADATA.
   virtual void SetReadMode(MediaCacheStream::ReadMode aMode) = 0;
 
   // Returns true if the resource can be seeked to unbuffered ranges, i.e.
   // for an HTTP network stream this returns true if HTTP1.1 Byte Range
   // requests are supported by the connection/server.
   virtual bool IsTransportSeekable() = 0;
 
   // Get the current principal for the channel

--- a/dom/media/ChannelMediaDecoder.cpp
+++ b/dom/media/ChannelMediaDecoder.cpp
@@ -250,19 +250,16 @@ ChannelMediaDecoder::Load(nsIChannel* aC
   nsresult rv = MediaShutdownManager::Instance().Register(this);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
   rv = mResource->Open(aStreamListener);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  // Set mode to METADATA since we are about to read metadata.
-  mResource->SetReadMode(MediaCacheStream::MODE_METADATA);
-
   SetStateMachine(CreateStateMachine());
   NS_ENSURE_TRUE(GetStateMachine(), NS_ERROR_FAILURE);
 
   return InitializeStateMachine();
 }
 
 nsresult
 ChannelMediaDecoder::Load(BaseMediaResource* aOriginal)

--- a/dom/media/MediaCache.cpp
+++ b/dom/media/MediaCache.cpp
@@ -502,17 +502,16 @@ MediaCacheStream::MediaCacheStream(Chann
   : mMediaCache(nullptr)
   , mClient(aClient)
   , mIsTransportSeekable(false)
   , mCacheSuspended(false)
   , mChannelEnded(false)
   , mStreamOffset(0)
   , mPlaybackBytesPerSecond(10000)
   , mPinCount(0)
-  , mCurrentMode(MODE_PLAYBACK)
   , mMetadataInPartialBlockBuffer(false)
   , mIsPrivateBrowsing(aIsPrivateBrowsing)
 {
 }
 
 size_t MediaCacheStream::SizeOfExcludingThis(
                                 MallocSizeOf aMallocSizeOf) const
 {

--- a/dom/media/MediaCache.h
+++ b/dom/media/MediaCache.h
@@ -518,17 +518,17 @@ private:
   // corresponding Unpin
   uint32_t          mPinCount;
   // True if CacheClientNotifyDataEnded has been called for this stream.
   bool              mDidNotifyDataEnded = false;
   // The status used when we did CacheClientNotifyDataEnded. Only valid
   // when mDidNotifyDataEnded is true.
   nsresult          mNotifyDataEndedStatus;
   // The last reported read mode
-  ReadMode          mCurrentMode;
+  ReadMode mCurrentMode = MODE_METADATA;
   // True if some data in mPartialBlockBuffer has been read as metadata
   bool              mMetadataInPartialBlockBuffer;
   // The load ID of the current channel. Used to check whether the data is
   // coming from an old channel and should be discarded.
   uint32_t mLoadID = 0;
   // The seek target initiated by MediaCache. -1 if no seek is going on.
   int64_t mSeekTarget = -1;