Bug 875911 - Clean up OfflineAudioContexts which have never been rendered; r=roc

content/media/MediaStreamGraph.cpp

@@ -957,8 +957,6 @@ MediaStreamGraphImpl::RunThread()
   if (!mRealtime) {
     NS_ASSERTION(!mNonRealtimeIsRunning,
                  "We should not be running in non-realtime mode already");
-    NS_ASSERTION(mNonRealtimeTicksToProcess,
-                 "We should have a non-zero number of ticks to process");
     mNonRealtimeIsRunning = true;
   }
 
@@ -1067,7 +1065,7 @@ MediaStreamGraphImpl::RunThread()
     }
     if (!mRealtime) {
       // Terminate processing if we've produce enough non-realtime ticks.
-      if (ticksProcessed >= mNonRealtimeTicksToProcess) {
+      if (!mForceShutDown && ticksProcessed >= mNonRealtimeTicksToProcess) {
         // Wait indefinitely when we've processed enough non-realtime ticks.
         // We'll be woken up when the graph shuts down.
         MonitorAutoLock lock(mMonitor);
@@ -2087,6 +2085,10 @@ MediaStreamGraph::DestroyNonRealtimeInstance(MediaStreamGraph* aGraph)
   MOZ_ASSERT(aGraph != gGraph, "Should not destroy the global graph here");
 
   MediaStreamGraphImpl* graph = static_cast<MediaStreamGraphImpl*>(aGraph);
+  if (!graph->mNonRealtimeProcessing) {
+    // Start the graph, but don't produce anything
+    graph->StartNonRealtimeProcessing(0);
+  }
   graph->ForceShutDown();
 }
 

content/media/test/crashtests/875911.html

@@ -0,0 +1,3 @@
+<script>
+  new OfflineAudioContext(1, 10, 48000);
+</script>

content/media/test/crashtests/crashtests.list

@@ -21,3 +21,4 @@ load 874934.html
 load 874952.html
 load 875144.html
 load 875596.html
+load 875911.html