--- a/dom/media/MediaCache.cpp
+++ b/dom/media/MediaCache.cpp
@@ -436,17 +436,16 @@ MediaCacheFlusher::Observe(nsISupports *
   }
   return NS_OK;
 }
 
 MediaCacheStream::MediaCacheStream(ChannelMediaResource* aClient,
                                    bool aIsPrivateBrowsing)
   : mMediaCache(nullptr)
   , mClient(aClient)
-  , mInitialized(false)
   , mHasHadUpdate(false)
   , mClosed(false)
   , mDidNotifyDataEnded(false)
   , mResourceID(0)
   , mIsTransportSeekable(false)
   , mCacheSuspended(false)
   , mChannelEnded(false)
   , mChannelOffset(0)
@@ -2067,18 +2066,19 @@ MediaCacheStream::AreAllStreamsForResour
   return true;
 }
 
 void
 MediaCacheStream::Close()
 {
   NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
 
-  if (!mInitialized)
+  if (!mMediaCache) {
     return;
+  }
 
   ReentrantMonitorAutoEnter mon(mMediaCache->GetReentrantMonitor());
   CloseInternal(mon);
   // Queue an Update since we may have created more free space. Don't do
   // it from CloseInternal since that gets called by Update() itself
   // sometimes, and we try to not to queue updates from Update().
   mMediaCache->QueueUpdate();
 }
@@ -2495,36 +2495,37 @@ MediaCacheStream::ReadFromCache(char* aB
   return NS_OK;
 }
 
 nsresult
 MediaCacheStream::Init()
 {
   NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
 
-  if (mInitialized)
+  if (mMediaCache) {
     return NS_OK;
+  }
 
   mMediaCache = MediaCache::GetMediaCache();
   if (!mMediaCache) {
     return NS_ERROR_FAILURE;
   }
   mMediaCache->OpenStream(this);
-  mInitialized = true;
   return NS_OK;
 }
 
 nsresult
 MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal)
 {
   if (!aOriginal->IsAvailableForSharing())
     return NS_ERROR_FAILURE;
 
-  if (mInitialized)
+  if (mMediaCache) {
     return NS_OK;
+  }
 
   nsresult rv = Init();
   if (NS_FAILED(rv))
     return rv;
   mResourceID = aOriginal->mResourceID;
 
   // Grab cache blocks from aOriginal as readahead blocks for our stream
   ReentrantMonitorAutoEnter mon(mMediaCache->GetReentrantMonitor());

--- a/dom/media/MediaCache.h
+++ b/dom/media/MediaCache.h
@@ -439,18 +439,16 @@ private:
   bool UpdatePrincipal(nsIPrincipal* aPrincipal);
 
   // Instance of MediaCache to use with this MediaCacheStream.
   MediaCache* mMediaCache;
 
   // These fields are main-thread-only.
   ChannelMediaResource*  mClient;
   nsCOMPtr<nsIPrincipal> mPrincipal;
-  // Set to true when Init or InitAsClone has been called
-  bool                   mInitialized;
   // Set to true when MediaCache::Update() has finished while this stream
   // was present.
   bool                   mHasHadUpdate;
   // Set to true when the stream has been closed either explicitly or
   // due to an internal cache error
   bool                   mClosed;
   // True if CacheClientNotifyDataEnded has been called for this stream.
   bool                   mDidNotifyDataEnded;