Bug 1078354 - Part 2 - Don't try to measure a PeriodicWave size when an OscillatorNode is using a basic waveform. r=erahm

--HG--
extra : rebase_source : 97028d8c6afd84dd71c8718305c074504d164da6

content/media/webaudio/OscillatorNode.cpp

@@ -553,7 +553,9 @@ OscillatorNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
   size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
 
   // For now only report if we know for sure that it's not shared.
-  amount += mPeriodicWave->SizeOfIncludingThisIfNotShared(aMallocSizeOf);
+  if (mPeriodicWave) {
+    amount += mPeriodicWave->SizeOfIncludingThisIfNotShared(aMallocSizeOf);
+  }
   amount += mFrequency->SizeOfIncludingThis(aMallocSizeOf);
   amount += mDetune->SizeOfIncludingThis(aMallocSizeOf);
   return amount;