--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -325,37 +325,37 @@ MediaDecoder::UpdateDormantState(bool aD
       !mOwner->GetVideoFrameContainer() ||
       (mOwner->GetMediaElement() && mOwner->GetMediaElement()->IsBeingDestroyed()) ||
       !mDormantSupported)
   {
     return;
   }
 
   DECODER_LOG("UpdateDormantState aTimeout=%d aActivity=%d mIsDormant=%d "
-              "ownerActive=%d ownerHidden=%d mIsHeuristicDormant=%d "
+              "ownerActive=%d mIsVisible=%d mIsHeuristicDormant=%d "
               "mPlayState=%s encrypted=%s",
               aDormantTimeout, aActivity, mIsDormant, mOwner->IsActive(),
-              mOwner->IsHidden(), mIsHeuristicDormant, PlayStateStr(),
+              mIsVisible, mIsHeuristicDormant, PlayStateStr(),
               (!mInfo ? "Unknown" : (mInfo->IsEncrypted() ? "1" : "0")));
 
   bool prevDormant = mIsDormant;
   mIsDormant = false;
   if (!mOwner->IsActive()) {
     mIsDormant = true;
   }
 #ifdef MOZ_WIDGET_GONK
   if (mOwner->IsHidden()) {
     mIsDormant = true;
   }
 #endif
 
   // Try to enable dormant by idle heuristic, when the owner is hidden.
   bool prevHeuristicDormant = mIsHeuristicDormant;
   mIsHeuristicDormant = false;
-  if (IsHeuristicDormantSupported() && mOwner->IsHidden()) {
+  if (IsHeuristicDormantSupported() && !mIsVisible) {
     if (aDormantTimeout && !aActivity &&
         (mPlayState == PLAY_STATE_PAUSED || IsEnded())) {
       // Enable heuristic dormant
       mIsHeuristicDormant = true;
     } else if(prevHeuristicDormant && !aActivity) {
       // Continue heuristic dormant
       mIsHeuristicDormant = true;
     }
@@ -401,17 +401,17 @@ MediaDecoder::StartDormantTimer()
 {
   MOZ_ASSERT(NS_IsMainThread());
   if (!IsHeuristicDormantSupported()) {
     return;
   }
 
   if (mIsHeuristicDormant ||
       mShuttingDown ||
-      !mOwner->IsHidden() ||
+      mIsVisible ||
       (mPlayState != PLAY_STATE_PAUSED &&
        !IsEnded()))
   {
     return;
   }
 
   if (!mDormantTimer) {
     mDormantTimer = do_CreateInstance("@mozilla.org/timer;1");
@@ -567,16 +567,17 @@ MediaDecoder::MediaDecoder(MediaDecoderO
   , mPlaybackRateReliable(AbstractThread::MainThread(), true,
                           "MediaDecoder::mPlaybackRateReliable (Canonical)")
   , mDecoderPosition(AbstractThread::MainThread(), 0,
                      "MediaDecoder::mDecoderPosition (Canonical)")
   , mMediaSeekable(AbstractThread::MainThread(), true,
                    "MediaDecoder::mMediaSeekable (Canonical)")
   , mMediaSeekableOnlyInBufferedRanges(AbstractThread::MainThread(), false,
                    "MediaDecoder::mMediaSeekableOnlyInBufferedRanges (Canonical)")
+  , mIsVisible(!mOwner->IsHidden())
   , mTelemetryReported(false)
 {
   MOZ_COUNT_CTOR(MediaDecoder);
   MOZ_ASSERT(NS_IsMainThread());
   MediaMemoryTracker::AddMediaDecoder(this);
 
   mAudioChannel = AudioChannelService::GetDefaultAudioChannel();
   mResourceCallback->Connect(this);

--- a/dom/media/MediaDecoder.h
+++ b/dom/media/MediaDecoder.h
@@ -801,16 +801,18 @@ protected:
   Canonical<int64_t> mDecoderPosition;
 
   // True if the media is seekable (i.e. supports random access).
   Canonical<bool> mMediaSeekable;
 
   // True if the media is only seekable within its buffered ranges.
   Canonical<bool> mMediaSeekableOnlyInBufferedRanges;
 
+  bool mIsVisible;
+
 public:
   AbstractCanonical<media::NullableTimeUnit>* CanonicalDurationOrNull() override;
   AbstractCanonical<double>* CanonicalVolume() {
     return &mVolume;
   }
   AbstractCanonical<double>* CanonicalPlaybackRate() {
     return &mPlaybackRate;
   }