--- a/dom/media/AudioStream.cpp
+++ b/dom/media/AudioStream.cpp
@@ -116,18 +116,16 @@ public:
 private:
   AutoTArray<Chunk, 7> mChunks;
   int64_t mBaseOffset;
   double mBasePosition;
 };
 
 AudioStream::AudioStream(DataSource& aSource)
   : mMonitor("AudioStream")
-  , mInRate(0)
-  , mOutRate(0)
   , mChannels(0)
   , mOutChannels(0)
   , mTimeStretcher(nullptr)
   , mDumpFile(nullptr)
   , mState(INITIALIZED)
   , mDataSource(aSource)
 {
 }
@@ -323,17 +321,16 @@ int AudioStream::InvokeCubeb(Function aF
 nsresult
 AudioStream::Init(uint32_t aNumChannels, uint32_t aRate,
                   const dom::AudioChannel aAudioChannel)
 {
   auto startTime = TimeStamp::Now();
   auto isFirst = CubebUtils::GetFirstStream();
 
   LOG("%s channels: %d, rate: %d", __FUNCTION__, aNumChannels, aRate);
-  mInRate = mOutRate = aRate;
   mChannels = aNumChannels;
   mOutChannels = aNumChannels;
 
   mDumpFile = OpenDumpFile(aNumChannels, aRate);
 
   cubeb_stream_params params;
   params.rate = aRate;
   params.channels = mOutChannels;

--- a/dom/media/AudioStream.h
+++ b/dom/media/AudioStream.h
@@ -274,20 +274,16 @@ private:
   void GetTimeStretched(AudioBufferWriter& aWriter);
 
   template <typename Function, typename... Args>
   int InvokeCubeb(Function aFunction, Args&&... aArgs);
 
   // The monitor is held to protect all access to member variables.
   Monitor mMonitor;
 
-  // Input rate in Hz (characteristic of the media being played)
-  uint32_t mInRate;
-  // Output rate in Hz (characteristic of the playback rate)
-  uint32_t mOutRate;
   uint32_t mChannels;
   uint32_t mOutChannels;
   AudioClock mAudioClock;
   soundtouch::SoundTouch* mTimeStretcher;
 
   // Output file for dumping audio
   FILE* mDumpFile;