--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -745,17 +745,17 @@ bool
 MediaFormatReader::NeedInput(DecoderData& aDecoder)
 {
   // We try to keep a few more compressed samples input than decoded samples
   // have been output, provided the state machine has requested we send it a
   // decoded sample. To account for H.264 streams which may require a longer
   // run of input than we input, decoders fire an "input exhausted" callback,
   // which overrides our "few more samples" threshold.
   return
-    !(aDecoder.mDraining || aDecoder.mDrainComplete) &&
+    !aDecoder.HasPendingDrain() &&
     !aDecoder.HasFatalError() &&
     aDecoder.mDecodingRequested &&
     !aDecoder.mDemuxRequest.Exists() &&
     !aDecoder.HasInternalSeekPending() &&
     aDecoder.mOutput.Length() <= aDecoder.mDecodeAhead &&
     (aDecoder.mInputExhausted || !aDecoder.mQueuedSamples.IsEmpty() ||
      aDecoder.mTimeThreshold.isSome() ||
      aDecoder.mNumSamplesInput - aDecoder.mNumSamplesOutput <= aDecoder.mDecodeAhead);
@@ -808,17 +808,17 @@ MediaFormatReader::UpdateReceivedNewData
   }
 
   if (decoder.mDemuxRequest.Exists()) {
     // We may have pending operations to process, so we want to continue
     // after UpdateReceivedNewData returns.
     return false;
   }
 
-  if (decoder.mDrainComplete || decoder.mDraining) {
+  if (decoder.HasPendingDrain()) {
     // We do not want to clear mWaitingForData or mDemuxEOS while
     // a drain is in progress in order to properly complete the operation.
     return false;
   }
 
   bool hasLastEnd;
   media::TimeUnit lastEnd = decoder.mTimeRanges.GetEnd(&hasLastEnd);
   if (hasLastEnd) {
@@ -1200,18 +1200,17 @@ MediaFormatReader::Update(TrackType aTra
       // Now that draining has completed, we check if we have received
       // new data again as the result may now be different from the earlier
       // run.
       if (UpdateReceivedNewData(aTrack) || decoder.mSeekRequest.Exists()) {
         LOGV("Nothing more to do");
         return;
       }
     } else if (decoder.mDemuxEOS && !decoder.mNeedDraining &&
-               !decoder.mDraining && !decoder.mDrainComplete &&
-               decoder.mQueuedSamples.IsEmpty()) {
+               !decoder.HasPendingDrain() && decoder.mQueuedSamples.IsEmpty()) {
       // It is possible to transition from WAITING_FOR_DATA directly to EOS
       // state during the internal seek; in which case no draining would occur.
       // There is no more samples left to be decoded and we are already in
       // EOS state. We can immediately reject the data promise.
       LOG("Rejecting %s promise: EOS", TrackTypeToStr(aTrack));
       decoder.RejectPromise(END_OF_STREAM, __func__);
     }
   }

--- a/dom/media/MediaFormatReader.h
+++ b/dom/media/MediaFormatReader.h
@@ -306,16 +306,21 @@ private:
     // rejected or prior a seek operation.
     bool mDecodingRequested;
     bool mOutputRequested;
     bool mInputExhausted;
     bool mNeedDraining;
     bool mDraining;
     bool mDrainComplete;
 
+    bool HasPendingDrain() const
+    {
+      return mDraining || mDrainComplete;
+    }
+
     uint32_t mNumOfConsecutiveError;
     uint32_t mMaxConsecutiveError;
 
     Maybe<MediaDataDecoderError> mError;
     bool HasFatalError() const
     {
       return mError.isSome() && mError.ref() == MediaDataDecoderError::FATAL_ERROR;
     }