Bug 1395195 - Restrict min number of channels on AudioCallbackDriver's helper buffers. r=padenot

MozReview-Commit-ID: 5eAhN4x6U4q

--HG--
extra : rebase_source : 0445dc820222ae51b74e277995baf423190cff7e

dom/media/GraphDriver.cpp

@@ -561,8 +561,8 @@ StreamAndPromiseForOperation::StreamAndPromiseForOperation(MediaStream* aStream,
 AudioCallbackDriver::AudioCallbackDriver(MediaStreamGraphImpl* aGraphImpl)
   : GraphDriver(aGraphImpl)
   , mOuputChannels(mGraphImpl->AudioChannelCount())
-  , mScratchBuffer(mOuputChannels)
-  , mBuffer(mOuputChannels)
+  , mScratchBuffer(std::max<uint32_t>(1, mOuputChannels))
+  , mBuffer(std::max<uint32_t>(1, mOuputChannels))
   , mSampleRate(0)
   , mInputChannels(1)
   , mIterationDurationMS(MEDIA_GRAPH_TARGET_PERIOD_MS)