Bug 1064966 - Initialize AudioCallbackDriver::mIterationDurationMS. r=jesup

--HG--
extra : rebase_source : 52d20570c6baa6503264e5ca55fabc8e492f3ea2

content/media/GraphDriver.cpp

@@ -520,6 +520,7 @@ AsyncCubebTask::Run()
 
 AudioCallbackDriver::AudioCallbackDriver(MediaStreamGraphImpl* aGraphImpl, dom::AudioChannel aChannel)
   : GraphDriver(aGraphImpl)
+  , mIterationDurationMS(MEDIA_GRAPH_TARGET_PERIOD_MS)
   , mStarted(false)
   , mAudioChannel(aChannel)
   , mInCallback(false)