Bug 1896762 - Make animation timing match the spec. r=smaug,firefox-animation-reviewers,boris

Differential Revision: https://phabricator.services.mozilla.com/D210658

dom/animation/DocumentTimeline.cpp

@@ -19,7 +19,6 @@ namespace mozilla::dom {
 NS_IMPL_CYCLE_COLLECTION_CLASS(DocumentTimeline)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(DocumentTimeline,
                                                 AnimationTimeline)
-  tmp->UnregisterFromRefreshDriver();
   if (tmp->isInList()) {
     tmp->remove();
   }
@@ -45,7 +44,6 @@ DocumentTimeline::DocumentTimeline(Document* aDocument,
     : AnimationTimeline(aDocument->GetParentObject(),
                         aDocument->GetScopeObject()->GetRTPCallerType()),
       mDocument(aDocument),
-      mIsObservingRefreshDriver(false),
       mOriginTime(aOriginTime) {
   if (mDocument) {
     mDocument->Timelines().insertBack(this);
@@ -55,9 +53,6 @@ DocumentTimeline::DocumentTimeline(Document* aDocument,
 }
 
 DocumentTimeline::~DocumentTimeline() {
-  MOZ_RELEASE_ASSERT(!mIsObservingRefreshDriver,
-                     "Timeline should have disassociated"
-                     " from the refresh driver before being destroyed");
   if (isInList()) {
     remove();
   }
@@ -105,11 +100,8 @@ TimeStamp DocumentTimeline::GetCurrentTimeStamp() const {
                        : mLastRefreshDriverTime;
 }
 
-void DocumentTimeline::UpdateLastRefreshDriverTime(TimeStamp aKnownTime) {
+void DocumentTimeline::UpdateLastRefreshDriverTime() {
   TimeStamp result = [&] {
-    if (!aKnownTime.IsNull()) {
-      return aKnownTime;
-    }
     if (auto* rd = GetRefreshDriver()) {
       return rd->MostRecentRefresh();
     };
@@ -157,110 +149,53 @@ Nullable<TimeDuration> DocumentTimeline::ToTimelineTime(
 void DocumentTimeline::NotifyAnimationUpdated(Animation& aAnimation) {
   AnimationTimeline::NotifyAnimationUpdated(aAnimation);
 
-  if (!mIsObservingRefreshDriver && !mAnimationOrder.isEmpty()) {
+  if (!mAnimationOrder.isEmpty()) {
-    nsRefreshDriver* refreshDriver = GetRefreshDriver();
+    if (nsRefreshDriver* refreshDriver = GetRefreshDriver()) {
-    if (refreshDriver) {
       MOZ_ASSERT(isInList(),
                  "We should not register with the refresh driver if we are not"
                  " in the document's list of timelines");
-
+      refreshDriver->EnsureAnimationUpdate();
-      ObserveRefreshDriver(refreshDriver);
     }
   }
 }
 
-void DocumentTimeline::MostRecentRefreshTimeUpdated() {
-  MOZ_ASSERT(mIsObservingRefreshDriver);
-  MOZ_ASSERT(GetRefreshDriver(),
-             "Should be able to reach refresh driver from within WillRefresh");
-
-  nsAutoAnimationMutationBatch mb(mDocument);
-
-  TickState state;
-  bool ticked = Tick(state);
-  if (!ticked) {
-    // We already assert that GetRefreshDriver() is non-null at the beginning
-    // of this function but we check it again here to be sure that ticking
-    // animations does not have any side effects that cause us to lose the
-    // connection with the refresh driver, such as triggering the destruction
-    // of mDocument's PresShell.
-    MOZ_ASSERT(GetRefreshDriver(),
-               "Refresh driver should still be valid at end of WillRefresh");
-    UnregisterFromRefreshDriver();
-  }
-}
-
 void DocumentTimeline::TriggerAllPendingAnimationsNow() {
   for (Animation* animation : mAnimationOrder) {
     animation->TryTriggerNow();
   }
 }
 
-void DocumentTimeline::WillRefresh(TimeStamp aTime) {
+void DocumentTimeline::WillRefresh() {
-  UpdateLastRefreshDriverTime();
+  if (!mDocument->GetPresShell()) {
-  MostRecentRefreshTimeUpdated();
+    // If we're not displayed, don't tick animations.
-}
-
-void DocumentTimeline::NotifyTimerAdjusted(TimeStamp aTime) {
-  MostRecentRefreshTimeUpdated();
-}
-
-void DocumentTimeline::ObserveRefreshDriver(nsRefreshDriver* aDriver) {
-  MOZ_RELEASE_ASSERT(!mIsObservingRefreshDriver,
-                     "shouldn't register as an observer more than once");
-  // Set the mIsObservingRefreshDriver flag before calling AddRefreshObserver
-  // since it might end up calling NotifyTimerAdjusted which calls
-  // MostRecentRefreshTimeUpdated which has an assertion for
-  // mIsObserveingRefreshDriver check.
-  mIsObservingRefreshDriver = true;
-  aDriver->AddRefreshObserver(this, FlushType::Style,
-                              "DocumentTimeline animations");
-  aDriver->AddTimerAdjustmentObserver(this);
-}
-
-void DocumentTimeline::NotifyRefreshDriverCreated(nsRefreshDriver* aDriver) {
-  MOZ_RELEASE_ASSERT(
-      !mIsObservingRefreshDriver,
-      "Timeline should not be observing the refresh driver before"
-      " it is created");
-
-  if (!mAnimationOrder.isEmpty()) {
-    MOZ_ASSERT(isInList(),
-               "We should not register with the refresh driver if we are not"
-               " in the document's list of timelines");
-    ObserveRefreshDriver(aDriver);
-    // Although we have started observing the refresh driver, it's possible we
-    // could perform a paint before the first refresh driver tick happens.  To
-    // ensure we're in a consistent state in that case we run the first tick
-    // manually.
-    MostRecentRefreshTimeUpdated();
-  }
-}
-
-void DocumentTimeline::DisconnectRefreshDriver(nsRefreshDriver* aDriver) {
-  MOZ_ASSERT(mIsObservingRefreshDriver);
-
-  aDriver->RemoveRefreshObserver(this, FlushType::Style);
-  aDriver->RemoveTimerAdjustmentObserver(this);
-  mIsObservingRefreshDriver = false;
-}
-
-void DocumentTimeline::NotifyRefreshDriverDestroying(nsRefreshDriver* aDriver) {
-  if (!mIsObservingRefreshDriver) {
     return;
   }
+  UpdateLastRefreshDriverTime();
+  if (mAnimationOrder.isEmpty()) {
+    return;
+  }
+  nsAutoAnimationMutationBatch mb(mDocument);
 
-  DisconnectRefreshDriver(aDriver);
+  TickState state;
+  bool ticked = Tick(state);
+  if (!ticked) {
+    return;
+  }
+  // We already assert that GetRefreshDriver() is non-null at the beginning
+  // of this function but we check it again here to be sure that ticking
+  // animations does not have any side effects that cause us to lose the
+  // connection with the refresh driver, such as triggering the destruction
+  // of mDocument's PresShell.
+  if (nsRefreshDriver* refreshDriver = GetRefreshDriver()) {
+    refreshDriver->EnsureAnimationUpdate();
+  } else {
+    MOZ_ASSERT_UNREACHABLE(
+        "Refresh driver should still be valid at end of WillRefresh");
+  }
 }
 
 void DocumentTimeline::RemoveAnimation(Animation* aAnimation) {
   AnimationTimeline::RemoveAnimation(aAnimation);
-
-  if (!mIsObservingRefreshDriver || !mAnimationOrder.isEmpty()) {
-    return;
-  }
-
-  UnregisterFromRefreshDriver();
 }
 
 void DocumentTimeline::NotifyAnimationContentVisibilityChanged(
@@ -268,19 +203,11 @@ void DocumentTimeline::NotifyAnimationContentVisibilityChanged(
   AnimationTimeline::NotifyAnimationContentVisibilityChanged(aAnimation,
                                                              aIsVisible);
 
-  if (mIsObservingRefreshDriver && mAnimationOrder.isEmpty()) {
+  if (nsRefreshDriver* refreshDriver = GetRefreshDriver()) {
-    UnregisterFromRefreshDriver();
+    MOZ_ASSERT(isInList(),
-  }
+               "We should not register with the refresh driver if we are not"
-
+               " in the document's list of timelines");
-  if (!mIsObservingRefreshDriver && !mAnimationOrder.isEmpty()) {
+    refreshDriver->EnsureAnimationUpdate();
-    nsRefreshDriver* refreshDriver = GetRefreshDriver();
-    if (refreshDriver) {
-      MOZ_ASSERT(isInList(),
-                 "We should not register with the refresh driver if we are not"
-                 " in the document's list of timelines");
-
-      ObserveRefreshDriver(refreshDriver);
-    }
   }
 }
 
@@ -302,20 +229,7 @@ nsRefreshDriver* DocumentTimeline::GetRefreshDriver() const {
   if (MOZ_UNLIKELY(!presContext)) {
     return nullptr;
   }
-
   return presContext->RefreshDriver();
 }
 
-void DocumentTimeline::UnregisterFromRefreshDriver() {
-  if (!mIsObservingRefreshDriver) {
-    return;
-  }
-
-  nsRefreshDriver* refreshDriver = GetRefreshDriver();
-  if (!refreshDriver) {
-    return;
-  }
-  DisconnectRefreshDriver(refreshDriver);
-}
-
 }  // namespace mozilla::dom

dom/animation/DocumentTimeline.h

@@ -14,15 +14,12 @@
 #include "AnimationTimeline.h"
 #include "nsDOMNavigationTiming.h"  // for DOMHighResTimeStamp
 #include "nsRefreshDriver.h"
-#include "nsRefreshObservers.h"
 
 struct JSContext;
 
 namespace mozilla::dom {
 
 class DocumentTimeline final : public AnimationTimeline,
-                               public nsARefreshObserver,
-                               public nsATimerAdjustmentObserver,
                                public LinkedListElement<DocumentTimeline> {
  public:
   DocumentTimeline(Document* aDocument, const TimeDuration& aOriginTime);
@@ -35,8 +32,7 @@ class DocumentTimeline final : public AnimationTimeline,
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(DocumentTimeline,
                                                          AnimationTimeline)
 
-  virtual JSObject* WrapObject(JSContext* aCx,
+  JSObject* WrapObject(JSContext*, JS::Handle<JSObject*> aGivenProto) override;
-                               JS::Handle<JSObject*> aGivenProto) override;
 
   static already_AddRefed<DocumentTimeline> Constructor(
       const GlobalObject& aGlobal, const DocumentTimelineOptions& aOptions,
@@ -46,7 +42,7 @@ class DocumentTimeline final : public AnimationTimeline,
 
   // This is deliberately _not_ called GetCurrentTime since that would clash
   // with a macro defined in winbase.h
-  virtual Nullable<TimeDuration> GetCurrentTimeAsDuration() const override;
+  Nullable<TimeDuration> GetCurrentTimeAsDuration() const override;
 
   bool TracksWallclockTime() const override;
   Nullable<TimeDuration> ToTimelineTime(
@@ -61,27 +57,17 @@ class DocumentTimeline final : public AnimationTimeline,
 
   void TriggerAllPendingAnimationsNow();
 
-  // nsARefreshObserver methods
+  void WillRefresh();
-  void WillRefresh(TimeStamp aTime) override;
-  // nsATimerAdjustmentObserver methods
-  void NotifyTimerAdjusted(TimeStamp aTime) override;
-
-  void NotifyRefreshDriverCreated(nsRefreshDriver* aDriver);
-  void NotifyRefreshDriverDestroying(nsRefreshDriver* aDriver);
 
   Document* GetDocument() const override { return mDocument; }
 
-  void UpdateLastRefreshDriverTime(TimeStamp aKnownTime = {});
+  void UpdateLastRefreshDriverTime();
 
   bool IsMonotonicallyIncreasing() const override { return true; }
 
  protected:
   TimeStamp GetCurrentTimeStamp() const;
   nsRefreshDriver* GetRefreshDriver() const;
-  void UnregisterFromRefreshDriver();
-  void MostRecentRefreshTimeUpdated();
-  void ObserveRefreshDriver(nsRefreshDriver* aDriver);
-  void DisconnectRefreshDriver(nsRefreshDriver* aDriver);
 
   RefPtr<Document> mDocument;
 
@@ -89,8 +75,6 @@ class DocumentTimeline final : public AnimationTimeline,
   // we don't have a refresh driver (e.g. because we are in a display:none
   // iframe).
   TimeStamp mLastRefreshDriverTime;
-  bool mIsObservingRefreshDriver;
-
   TimeDuration mOriginTime;
 };
 

dom/animation/test/chrome/test_running_on_compositor.html

@@ -88,11 +88,12 @@ promise_test(async t => {
   div.style.animationPlayState = 'paused';
 
   await animation.ready;
+  await waitForPaints();
 
   assert_animation_is_not_running_on_compositor(animation,
      'Animation reports that it is NOT running on the compositor'
      + ' when paused');
-}, '');
+}, 'Basic test');
 
 promise_test(async t => {
   var div = addDiv(t, { style: 'animation: z-index 100s' });
@@ -127,6 +128,8 @@ promise_test(async t => {
   animation.pause();
   await animation.ready;
 
+  await waitForPaints();
+
   assert_animation_is_not_running_on_compositor(animation,
      'Animation reports that it is NOT running on the compositor'
      + ' when animation.pause() is called');

layout/base/PresShell.cpp

@@ -994,8 +994,8 @@ void PresShell::Init(nsPresContext* aPresContext, nsViewManager* aViewManager) {
     animCtrl->NotifyRefreshDriverCreated(GetPresContext()->RefreshDriver());
   }
 
-  for (DocumentTimeline* timeline : mDocument->Timelines()) {
+  for (DocumentTimeline* timelines : mDocument->Timelines()) {
-    timeline->NotifyRefreshDriverCreated(GetPresContext()->RefreshDriver());
+    timelines->UpdateLastRefreshDriverTime();
   }
 
   // Get our activeness from the docShell.
@@ -1338,9 +1338,6 @@ void PresShell::Destroy() {
     if (mDocument->HasAnimationController()) {
       mDocument->GetAnimationController()->NotifyRefreshDriverDestroying(rd);
     }
-    for (DocumentTimeline* timeline : mDocument->Timelines()) {
-      timeline->NotifyRefreshDriverDestroying(rd);
-    }
   }
 
   if (mPresContext) {

layout/base/nsRefreshDriver.cpp

@@ -50,6 +50,7 @@
 #include "nsComponentManagerUtils.h"
 #include "mozilla/Logging.h"
 #include "mozilla/dom/Document.h"
+#include "mozilla/dom/DocumentTimeline.h"
 #include "mozilla/dom/DocumentInlines.h"
 #include "nsIXULRuntime.h"
 #include "jsapi.h"
@@ -1364,6 +1365,7 @@ nsRefreshDriver::nsRefreshDriver(nsPresContext* aPresContext)
       mNotifyDOMContentFlushed(false),
       mNeedToUpdateIntersectionObservations(false),
       mNeedToUpdateResizeObservers(false),
+      mNeedToUpdateAnimations(false),
       mMightNeedMediaQueryListenerUpdate(false),
       mNeedToUpdateContentRelevancy(false),
       mInNormalTick(false),
@@ -1489,18 +1491,6 @@ bool nsRefreshDriver::RemoveRefreshObserver(nsARefreshObserver* aObserver,
   return true;
 }
 
-void nsRefreshDriver::AddTimerAdjustmentObserver(
-    nsATimerAdjustmentObserver* aObserver) {
-  MOZ_ASSERT(!mTimerAdjustmentObservers.Contains(aObserver));
-  mTimerAdjustmentObservers.AppendElement(aObserver);
-}
-
-void nsRefreshDriver::RemoveTimerAdjustmentObserver(
-    nsATimerAdjustmentObserver* aObserver) {
-  MOZ_ASSERT(mTimerAdjustmentObservers.Contains(aObserver));
-  mTimerAdjustmentObservers.RemoveElement(aObserver);
-}
-
 void nsRefreshDriver::PostVisualViewportResizeEvent(
     VVPResizeEvent* aResizeEvent) {
   mVisualViewportResizeEvents.AppendElement(aResizeEvent);
@@ -1885,11 +1875,6 @@ void nsRefreshDriver::EnsureTimerStarted(EnsureTimerStartedFlags aFlags) {
 
   if (mMostRecentRefresh != mActiveTimer->MostRecentRefresh()) {
     mMostRecentRefresh = mActiveTimer->MostRecentRefresh();
-
-    for (nsATimerAdjustmentObserver* obs :
-         mTimerAdjustmentObservers.EndLimitedRange()) {
-      obs->NotifyTimerAdjusted(mMostRecentRefresh);
-    }
   }
 }
 
@@ -1919,7 +1904,6 @@ uint32_t nsRefreshDriver::ObserverCount() const {
   sum += mThrottledFrameRequestCallbackDocs.Length();
   sum += mViewManagerFlushIsPending;
   sum += mEarlyRunners.Length();
-  sum += mTimerAdjustmentObservers.Length();
   sum += mAutoFocusFlushDocuments.Length();
   return sum;
 }
@@ -2011,6 +1995,9 @@ auto nsRefreshDriver::GetReasonsToTick() const -> TickReasons {
   if (mNeedToUpdateResizeObservers) {
     reasons |= TickReasons::eNeedsToNotifyResizeObservers;
   }
+  if (mNeedToUpdateAnimations) {
+    reasons |= TickReasons::eNeedsToUpdateAnimations;
+  }
   if (mNeedToUpdateIntersectionObservations) {
     reasons |= TickReasons::eNeedsToUpdateIntersectionObservations;
   }
@@ -2054,6 +2041,9 @@ void nsRefreshDriver::AppendTickReasonsToString(TickReasons aReasons,
   if (aReasons & TickReasons::eNeedsToNotifyResizeObservers) {
     aStr.AppendLiteral(" NeedsToNotifyResizeObservers");
   }
+  if (aReasons & TickReasons::eNeedsToUpdateAnimations) {
+    aStr.AppendLiteral(" NeedsToUpdateAnimations");
+  }
   if (aReasons & TickReasons::eNeedsToUpdateIntersectionObservations) {
     aStr.AppendLiteral(" NeedsToUpdateIntersectionObservations");
   }
@@ -2344,11 +2334,41 @@ void nsRefreshDriver::DetermineProximityToViewportAndNotifyResizeObservers() {
   }
 }
 
-void nsRefreshDriver::DispatchAnimationEvents() {
+static CallState UpdateAndReduceAnimations(Document& aDocument) {
+  for (DocumentTimeline* timeline : aDocument.Timelines()) {
+    timeline->WillRefresh();
+  }
+
+  if (nsPresContext* pc = aDocument.GetPresContext()) {
+    if (pc->EffectCompositor()->NeedsReducing()) {
+      pc->EffectCompositor()->ReduceAnimations();
+    }
+  }
+  aDocument.EnumerateSubDocuments(UpdateAndReduceAnimations);
+  return CallState::Continue;
+}
+
+void nsRefreshDriver::UpdateAnimationsAndSendEvents() {
+  // TODO(emilio): Can we early-return here if mNeedToUpdateAnimations is
+  // already false?
+  mNeedToUpdateAnimations = false;
   if (!mPresContext) {
     return;
   }
 
+  {
+    // Animation updates may queue Promise resolution microtasks. We shouldn't
+    // run these, however, until we have fully updated the animation state. As
+    // per the "update animations and send events" procedure[1], we should
+    // remove replaced animations and then run these microtasks before
+    // dispatching the corresponding animation events.
+    //
+    // [1]:
+    // https://drafts.csswg.org/web-animations-1/#update-animations-and-send-events
+    nsAutoMicroTask mt;
+    UpdateAndReduceAnimations(*mPresContext->Document());
+  }
+
   // Hold all AnimationEventDispatcher in mAnimationEventFlushObservers as
   // a RefPtr<> array since each AnimationEventDispatcher might be destroyed
   // during processing the previous dispatcher.
@@ -2495,16 +2515,6 @@ void nsRefreshDriver::CancelIdleTask(Task* aTask) {
   }
 }
 
-static CallState ReduceAnimations(Document& aDocument) {
-  if (nsPresContext* pc = aDocument.GetPresContext()) {
-    if (pc->EffectCompositor()->NeedsReducing()) {
-      pc->EffectCompositor()->ReduceAnimations();
-    }
-  }
-  aDocument.EnumerateSubDocuments(ReduceAnimations);
-  return CallState::Continue;
-}
-
 bool nsRefreshDriver::TickObserverArray(uint32_t aIdx, TimeStamp aNowTime) {
   MOZ_ASSERT(aIdx < ArrayLength(mObservers));
   for (RefPtr<nsARefreshObserver> obs : mObservers[aIdx].EndLimitedRange()) {
@@ -2667,28 +2677,6 @@ void nsRefreshDriver::Tick(VsyncId aId, TimeStamp aNowTime,
     return StopTimer();
   }
 
-  // Any animation timelines updated above (animation timelines are style flush
-  // observers) may cause animations to queue Promise resolution microtasks. We
-  // shouldn't run these, however, until we have fully updated the animation
-  // state.
-  //
-  // As per the "update animations and send events" procedure[1], we should
-  // remove replaced animations and then run these microtasks before
-  // dispatching the corresponding animation events.
-  //
-  // FIXME(emilio, bug 1896762): This comment doesn't make much sense to me.
-  // We're running micro-tasks in the block below, but we don't "Update
-  // animations and send events" until we hit DispatchAnimationEvents() below.
-  // We should probably refactor the setup so that animation timelines are
-  // ticked as part of step 11 below or so, and do this only then.
-  //
-  // [1]:
-  // https://drafts.csswg.org/web-animations-1/#update-animations-and-send-events
-  {
-    nsAutoMicroTask mt;
-    ReduceAnimations(*mPresContext->Document());
-  }
-
   // Check if running the microtask checkpoint above caused the pres context to
   // be destroyed.
   if (!mPresContext || !mPresContext->GetPresShell()) {
@@ -2713,7 +2701,7 @@ void nsRefreshDriver::Tick(VsyncId aId, TimeStamp aNowTime,
   EvaluateMediaQueriesAndReportChanges();
 
   // Step 11. For each doc of docs, update animations and send events for doc.
-  DispatchAnimationEvents();
+  UpdateAnimationsAndSendEvents();
 
   // Step 12. For each doc of docs, run the fullscreen steps for doc.
   RunFullscreenSteps();

layout/base/nsRefreshDriver.h

@@ -103,12 +103,6 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
                           const char* aObserverDescription);
   bool RemoveRefreshObserver(nsARefreshObserver* aObserver,
                              mozilla::FlushType aFlushType);
-  /**
-   * Add / remove an observer wants to know the time when the refresh driver
-   * updated the most recent refresh time due to its active timer changes.
-   */
-  void AddTimerAdjustmentObserver(nsATimerAdjustmentObserver* aObserver);
-  void RemoveTimerAdjustmentObserver(nsATimerAdjustmentObserver* aObserver);
 
   void PostVisualViewportResizeEvent(VVPResizeEvent* aResizeEvent);
   void DispatchVisualViewportResizeEvents();
@@ -417,6 +411,11 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
     mNeedToUpdateResizeObservers = true;
   }
 
+  void EnsureAnimationUpdate() {
+    EnsureTimerStarted();
+    mNeedToUpdateAnimations = true;
+  }
+
   void ScheduleMediaQueryListenerUpdate() {
     EnsureTimerStarted();
     mMightNeedMediaQueryListenerUpdate = true;
@@ -446,6 +445,7 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
     eHasPendingMediaQueryListeners = 1 << 7,
     eNeedsToNotifyResizeObservers = 1 << 8,
     eRootNeedsMoreTicksForUserInput = 1 << 9,
+    eNeedsToUpdateAnimations = 1 << 10,
   };
 
   void AddForceNotifyContentfulPaintPresContext(nsPresContext* aPresContext);
@@ -487,7 +487,7 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
   MOZ_CAN_RUN_SCRIPT
   void FlushAutoFocusDocuments();
   void RunFullscreenSteps();
-  void DispatchAnimationEvents();
+  void UpdateAnimationsAndSendEvents();
   MOZ_CAN_RUN_SCRIPT
   void RunFrameRequestCallbacks(mozilla::TimeStamp aNowTime);
   void UpdateIntersectionObservations(mozilla::TimeStamp aNowTime);
@@ -643,6 +643,9 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
   // all our documents.
   bool mNeedToUpdateResizeObservers : 1;
 
+  // True if we need to update animations.
+  bool mNeedToUpdateAnimations : 1;
+
   // True if we might need to report media query changes in any of our
   // documents.
   bool mMightNeedMediaQueryListenerUpdate : 1;
@@ -673,12 +676,6 @@ class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
 
   // separate arrays for each flush type we support
   ObserverArray mObservers[3];
-  // These observers should NOT be included in HasObservers() since that method
-  // is used to determine whether or not to stop the timer, or restore it when
-  // thawing the refresh driver. On the other hand these observers are intended
-  // to be called when the timer is re-started and should not influence its
-  // starting or stopping.
-  nsTObserverArray<nsATimerAdjustmentObserver*> mTimerAdjustmentObservers;
   nsTArray<mozilla::layers::CompositionPayload> mCompositionPayloads;
   RequestTable mRequests;
   ImageStartTable mStartTable;

layout/base/nsRefreshObservers.h

@@ -60,17 +60,6 @@ class nsARefreshObserver {
 #endif  // DEBUG
 };
 
-/**
- * An abstract base class to be implemented by callers wanting to be notified
- * when the observing refresh driver updated mMostRecentRefresh due to active
- * timer changes. Callers must ensure an observer is removed before it is
- * destroyed.
- */
-class nsATimerAdjustmentObserver {
- public:
-  virtual void NotifyTimerAdjusted(mozilla::TimeStamp aTime) = 0;
-};
-
 /**
  * An abstract base class to be implemented by callers wanting to be notified
  * that a refresh has occurred. Callers must ensure an observer is removed

layout/printing/nsPrintJob.cpp

@@ -20,6 +20,7 @@
 #include "mozilla/dom/ShadowRoot.h"
 #include "mozilla/dom/CustomEvent.h"
 #include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/DocumentTimeline.h"
 #include "mozilla/dom/HTMLCanvasElement.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/IntegerRange.h"
@@ -1414,6 +1415,10 @@ nsresult nsPrintJob::ReflowPrintObject(const UniquePtr<nsPrintObject>& aPO) {
       aPO->mPresContext->SetPageSize(pageSize);
     }
   }
+  // Make sure animations are active.
+  for (DocumentTimeline* tl : aPO->mDocument->Timelines()) {
+    tl->TriggerAllPendingAnimationsNow();
+  }
   // Process the reflow event Initialize posted
   presShell->FlushPendingNotifications(FlushType::Layout);
 

testing/web-platform/meta/dom/nodes/moveBefore/tentative/css-transition-cross-document.html.ini

@@ -1,16 +1,4 @@
 [css-transition-cross-document.html]
-  expected:
+  expected: [TIMEOUT, OK]
-    if (os == "linux") and debug and fission: [OK, TIMEOUT]
-    if (os == "linux") and debug and not fission: [OK, TIMEOUT]
-    if (os == "win") and not debug: TIMEOUT
-    if (os == "linux") and not debug: TIMEOUT
-    if os == "android": OK
-    [TIMEOUT, OK]
   [Moving a transition across documents should reset its state]
-    expected:
+    expected: [TIMEOUT, FAIL]
-      if (os == "linux") and debug and fission: [FAIL, TIMEOUT]
-      if (os == "linux") and debug and not fission: [FAIL, TIMEOUT]
-      if (os == "win") and not debug: TIMEOUT
-      if (os == "linux") and not debug: TIMEOUT
-      if os == "android": FAIL
-      [TIMEOUT, FAIL]