bug 1409622 initialize mTime even in Stream AudioTimelineEvents r=padenot

to avoid uninitialized read in WebAudioUtils::ConvertAudioTimelineEventToTicks()

MozReview-Commit-ID: GHPGIrc0T2h

--HG--
extra : rebase_source : 3b6e482cbab07b30a05c1156f95ab6965a59d545

dom/media/webaudio/AudioEventTimeline.cpp

@@ -85,6 +85,7 @@ AudioTimelineEvent::AudioTimelineEvent(MediaStream* aStream)
 #ifdef DEBUG
   , mTimeIsInTicks(false)
 #endif
+  , mTime(0.0)
 {
 }