Bug 1416643. P1 - remove checks for mDidNotifyDataEnded/mNotifyDataEndedStatus from IsAvailableForSharing(). r=bechen,gerald

We will need to modify these members off the main thead while IsAvailableForSharing()
is a main thread only function.

InitAsClone() will return an error if the original stream ends abnormally.

MozReview-Commit-ID: 1qRyboca2YZ

--HG--
extra : rebase_source : 4617a911a1de052833bd0085b883a8ae4d639c7d

dom/media/ChannelMediaResource.cpp

@@ -610,7 +610,11 @@ ChannelMediaResource::CloneData(MediaResourceCallback* aCallback)
   // which will recreate the channel. This way, if all of the media data
   // is already in the cache we don't create an unnecessary HTTP channel
   // and perform a useless HTTP transaction.
-  resource->mCacheStream.InitAsClone(&mCacheStream);
+  nsresult rv = resource->mCacheStream.InitAsClone(&mCacheStream);
+  if (NS_FAILED(rv)) {
+    resource->Close();
+    return nullptr;
+  }
   // mSuspendAgent.Suspend() accesses mCacheStream which is not ready
   // until InitAsClone() is done.
   resource->mSuspendAgent.Suspend();

dom/media/MediaCache.cpp

@@ -2697,13 +2697,19 @@ MediaCacheStream::Init(int64_t aContentLength)
   return NS_OK;
 }
 
-void
+nsresult
 MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal)
 {
   MOZ_ASSERT(aOriginal->IsAvailableForSharing());
   MOZ_ASSERT(!mMediaCache, "Has been initialized.");
   MOZ_ASSERT(aOriginal->mMediaCache, "Don't clone an uninitialized stream.");
 
+  if (aOriginal->mDidNotifyDataEnded &&
+      NS_FAILED(aOriginal->mNotifyDataEndedStatus)) {
+    // Streams that ended abnormally are ineligible for cloning.
+    return NS_ERROR_FAILURE;
+  }
+
   // This needs to be done before OpenStream() to avoid data race.
   mClientSuspended = true;
 
@@ -2744,6 +2750,8 @@ MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal)
   }
 
   mMediaCache->OpenStream(this, true /* aIsClone */);
+
+  return NS_OK;
 }
 
 nsIEventTarget*

dom/media/MediaCache.h

@@ -210,7 +210,7 @@ public:
   // as the aOriginal stream.
   // Exactly one of InitAsClone or Init must be called before any other method
   // on this class.
-  void InitAsClone(MediaCacheStream* aOriginal);
+  nsresult InitAsClone(MediaCacheStream* aOriginal);
 
   nsIEventTarget* OwnerThread() const;
 
@@ -223,11 +223,7 @@ public:
   bool IsClosed() const { return mClosed; }
   // Returns true when this stream is can be shared by a new resource load.
   // Called on the main thread only.
-  bool IsAvailableForSharing() const
-  {
-    return !mClosed && !mIsPrivateBrowsing &&
-      (!mDidNotifyDataEnded || NS_SUCCEEDED(mNotifyDataEndedStatus));
-  }
+  bool IsAvailableForSharing() const { return !mClosed && !mIsPrivateBrowsing; }
   // Get the principal for this stream. Anything accessing the contents of
   // this stream must have a principal that subsumes this principal.
   nsIPrincipal* GetCurrentPrincipal() { return mPrincipal; }