Bug 1408294 - Assert that NotifyPull produces data. r=padenot

MozReview-Commit-ID: CtC8A83iJgg

--HG--
extra : rebase_source : ada5a771164fafe35d22589956ced6f54545ee73

dom/media/MediaManager.cpp

@@ -3736,6 +3736,10 @@ SourceListener::Remove()
 
   // If it's destroyed, don't call - listener will be removed and we'll be notified!
   if (!mStream->IsDestroyed()) {
+    // We disable pulling before removing so we don't risk having live tracks
+    // without a listener attached - that wouldn't produce data and would be
+    // illegal to the graph.
+    mStream->SetPullEnabled(false);
     mStream->RemoveListener(this);
   }
 }

dom/media/MediaStreamGraph.cpp

@@ -1185,6 +1185,29 @@ MediaStreamGraphImpl::UpdateGraph(GraphTime aEndBlockingDecisions)
       }
     } else {
       stream->mStartBlocking = WillUnderrun(stream, aEndBlockingDecisions);
+
+      SourceMediaStream* s = stream->AsSourceStream();
+      if (s && s->mPullEnabled) {
+        for (StreamTracks::TrackIter i(s->mTracks); !i.IsEnded(); i.Next()) {
+          if (i->IsEnded()) {
+            continue;
+          }
+          if (i->GetEnd() < stream->GraphTimeToStreamTime(aEndBlockingDecisions)) {
+            LOG(LogLevel::Error,
+                ("SourceMediaStream %p track %u (%s) is live and pulled, but wasn't fed "
+                 "enough data. Listeners=%zu. Track-end=%f, Iteration-end=%f",
+                 stream,
+                 i->GetID(),
+                 (i->GetType() == MediaSegment::AUDIO ? "audio" : "video"),
+                 stream->mListeners.Length(),
+                 MediaTimeToSeconds(i->GetEnd()),
+                 MediaTimeToSeconds(stream->GraphTimeToStreamTime(aEndBlockingDecisions))));
+            MOZ_DIAGNOSTIC_ASSERT(false,
+                                  "A non-finished SourceMediaStream wasn't fed "
+                                  "enough data by NotifyPull");
+          }
+        }
+      }
     }
   }