--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -1042,27 +1042,16 @@ nsRefreshDriver::GetMinRecomputeVisibili
   int32_t interval =
     Preferences::GetInt("layout.visibility.min-recompute-interval-ms", -1);
   if (interval <= 0) {
     interval = DEFAULT_RECOMPUTE_VISIBILITY_INTERVAL_MS;
   }
   return TimeDuration::FromMilliseconds(interval);
 }
 
-/* static */ mozilla::TimeDuration
-nsRefreshDriver::GetMinNotifyIntersectionObserversInterval()
-{
-  int32_t interval =
-    Preferences::GetInt("layout.visibility.min-notify-intersection-observers-interval-ms", -1);
-  if (interval <= 0) {
-    interval = DEFAULT_NOTIFY_INTERSECTION_OBSERVERS_INTERVAL_MS;
-  }
-  return TimeDuration::FromMilliseconds(interval);
-}
-
 double
 nsRefreshDriver::GetRefreshTimerInterval() const
 {
   return mThrottled ? GetThrottledTimerInterval() : GetRegularTimerInterval();
 }
 
 RefreshDriverTimer*
 nsRefreshDriver::ChooseTimer() const
@@ -1093,18 +1082,16 @@ nsRefreshDriver::nsRefreshDriver(nsPresC
     mPresContext(aPresContext),
     mRootRefresh(nullptr),
     mPendingTransaction(0),
     mCompletedTransaction(0),
     mFreezeCount(0),
     mThrottledFrameRequestInterval(TimeDuration::FromMilliseconds(
                                      GetThrottledTimerInterval())),
     mMinRecomputeVisibilityInterval(GetMinRecomputeVisibilityInterval()),
-    mMinNotifyIntersectionObserversInterval(
-      GetMinNotifyIntersectionObserversInterval()),
     mThrottled(false),
     mNeedToRecomputeVisibility(false),
     mTestControllingRefreshes(false),
     mViewManagerFlushIsPending(false),
     mRequestedHighPrecision(false),
     mInRefresh(false),
     mWaitingForTransaction(false),
     mSkippedPaints(false),
@@ -1115,17 +1102,16 @@ nsRefreshDriver::nsRefreshDriver(nsPresC
   MOZ_ASSERT(mPresContext,
              "Need a pres context to tell us to call Disconnect() later "
              "and decrement sRefreshDriverCount.");
   mMostRecentRefreshEpochTime = JS_Now();
   mMostRecentRefresh = TimeStamp::Now();
   mMostRecentTick = mMostRecentRefresh;
   mNextThrottledFrameRequestTick = mMostRecentTick;
   mNextRecomputeVisibilityTick = mMostRecentTick;
-  mNextNotifyIntersectionObserversTick = mMostRecentTick;
 
   ++sRefreshDriverCount;
 }
 
 nsRefreshDriver::~nsRefreshDriver()
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(ObserverCount() == 0,
@@ -1890,30 +1876,22 @@ nsRefreshDriver::Tick(int64_t aNowEpoch,
       aNowTime >= mNextRecomputeVisibilityTick &&
       !presShell->IsPaintingSuppressed()) {
     mNextRecomputeVisibilityTick = aNowTime + mMinRecomputeVisibilityInterval;
     mNeedToRecomputeVisibility = false;
 
     presShell->ScheduleApproximateFrameVisibilityUpdateNow();
   }
 
-  bool notifyIntersectionObservers = false;
-  if (aNowTime >= mNextNotifyIntersectionObserversTick) {
-    mNextNotifyIntersectionObserversTick =
-      aNowTime + mMinNotifyIntersectionObserversInterval;
-    notifyIntersectionObservers = true;
-  }
   nsCOMArray<nsIDocument> documents;
   CollectDocuments(mPresContext->Document(), &documents);
   for (int32_t i = 0; i < documents.Count(); ++i) {
     nsIDocument* doc = documents[i];
     doc->UpdateIntersectionObservations();
-    if (notifyIntersectionObservers) {
-      doc->ScheduleIntersectionObserverNotification();
-    }
+    doc->ScheduleIntersectionObserverNotification();
   }
 
   /*
    * Perform notification to imgIRequests subscribed to listen
    * for refresh events.
    */
 
   for (auto iter = mStartTable.Iter(); !iter.Done(); iter.Next()) {

--- a/layout/base/nsRefreshDriver.h
+++ b/layout/base/nsRefreshDriver.h
@@ -402,17 +402,16 @@ private:
   // Trigger a refresh immediately, if haven't been disconnected or frozen.
   void DoRefresh();
 
   double GetRefreshTimerInterval() const;
   double GetRegularTimerInterval(bool *outIsDefault = nullptr) const;
   static double GetThrottledTimerInterval();
 
   static mozilla::TimeDuration GetMinRecomputeVisibilityInterval();
-  static mozilla::TimeDuration GetMinNotifyIntersectionObserversInterval();
 
   bool HaveFrameRequestCallbacks() const {
     return mFrameRequestCallbackDocs.Length() != 0;
   }
 
   void FinishedWaitingForTransaction();
 
   mozilla::RefreshDriverTimer* ChooseTimer() const;
@@ -438,18 +437,16 @@ private:
   const mozilla::TimeDuration mThrottledFrameRequestInterval;
 
   // How long we wait, at a minimum, before recomputing approximate frame
   // visibility information. This is a minimum because, regardless of this
   // interval, we only recompute visibility when we've seen a layout or style
   // flush since the last time we did it.
   const mozilla::TimeDuration mMinRecomputeVisibilityInterval;
 
-  const mozilla::TimeDuration mMinNotifyIntersectionObserversInterval;
-
   bool mThrottled;
   bool mNeedToRecomputeVisibility;
   bool mTestControllingRefreshes;
   bool mViewManagerFlushIsPending;
   bool mRequestedHighPrecision;
   bool mInRefresh;
 
   // True if the refresh driver is suspended waiting for transaction
@@ -470,17 +467,16 @@ private:
   // transaction to be completed before we append a note to the gfx critical log.
   // The number is doubled every time the threshold is hit.
   uint64_t mWarningThreshold;
   mozilla::TimeStamp mMostRecentRefresh;
   mozilla::TimeStamp mMostRecentTick;
   mozilla::TimeStamp mTickStart;
   mozilla::TimeStamp mNextThrottledFrameRequestTick;
   mozilla::TimeStamp mNextRecomputeVisibilityTick;
-  mozilla::TimeStamp mNextNotifyIntersectionObserversTick;
 
   // separate arrays for each flush type we support
   ObserverArray mObservers[3];
   RequestTable mRequests;
   ImageStartTable mStartTable;
 
   struct PendingEvent {
     nsCOMPtr<nsINode> mTarget;