Bug 1232577 part 10 - Remove AnimationCollection::mStyleChanging; r=heycam

This flag is no longer needed because in bug 1232563 we introduced a more
thorough optimization that detects when the animation is not changing by
comparing the progress value between samples and avoids requesting restyles
when it does not change.

dom/animation/Animation.cpp

@@ -682,19 +682,12 @@ Animation::HasLowerCompositeOrderThan(const Animation& aOther) const
 
 void
 Animation::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
-                        nsCSSPropertySet& aSetProperties,
-                        bool& aStyleChanging)
+                        nsCSSPropertySet& aSetProperties)
 {
   if (!mEffect) {
     return;
   }
 
-  AnimationPlayState playState = PlayState();
-  if (playState == AnimationPlayState::Running ||
-      playState == AnimationPlayState::Pending) {
-    aStyleChanging = true;
-  }
-
   if (!IsInEffect()) {
     return;
   }
@@ -734,6 +727,7 @@ Animation::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
   // afterwards. This is purely to prevent visual flicker. Other behavior
   // such as dispatching events continues to rely on the regular timeline time.
   bool updatedHoldTime = false;
+  AnimationPlayState playState = PlayState();
   {
     AutoRestore<Nullable<TimeDuration>> restoreHoldTime(mHoldTime);
 

dom/animation/Animation.h

@@ -307,13 +307,9 @@ public:
    * if any.
    * Any properties already contained in |aSetProperties| are not changed. Any
    * properties that are changed are added to |aSetProperties|.
-   * |aStyleChanging| will be set to true if this animation expects to update
-   * the style rule on the next refresh driver tick as well (because it
-   * is running and has an effect to sample).
    */
   void ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
-                    nsCSSPropertySet& aSetProperties,
-                    bool& aStyleChanging);
+                    nsCSSPropertySet& aSetProperties);
 
   void NotifyEffectTimingUpdated();
 

dom/animation/EffectCompositor.cpp

@@ -182,8 +182,7 @@ void
 EffectCompositor::MaybeUpdateAnimationRule(dom::Element* aElement,
                                            nsCSSPseudoElements::Type
                                              aPseudoType,
-                                           CascadeLevel aCascadeLevel,
-                                           bool& aStyleChanging)
+                                           CascadeLevel aCascadeLevel)
 {
   auto& elementsToRestyle = mElementsToRestyle[aCascadeLevel];
   PseudoElementHashKey key = { aElement, aPseudoType };
@@ -193,8 +192,7 @@ EffectCompositor::MaybeUpdateAnimationRule(dom::Element* aElement,
   }
 
   ComposeAnimationRule(aElement, aPseudoType, aCascadeLevel,
-                       mPresContext->RefreshDriver()->MostRecentRefresh(),
-                       aStyleChanging);
+                       mPresContext->RefreshDriver()->MostRecentRefresh());
 
   elementsToRestyle.Remove(key);
 }
@@ -360,8 +358,7 @@ EffectCompositor::GetAnimationElementAndPseudoForFrame(const nsIFrame* aFrame)
 EffectCompositor::ComposeAnimationRule(dom::Element* aElement,
                                        nsCSSPseudoElements::Type aPseudoType,
                                        CascadeLevel aCascadeLevel,
-                                       TimeStamp aRefreshTime,
-                                       bool& aStyleChanging)
+                                       TimeStamp aRefreshTime)
 {
   EffectSet* effects = EffectSet::GetEffectSet(aElement, aPseudoType);
   if (!effects) {
@@ -386,9 +383,6 @@ EffectCompositor::ComposeAnimationRule(dom::Element* aElement,
     effects->AnimationRule(aCascadeLevel);
   animationRule = nullptr;
 
-  // We'll set aStyleChanging to true below if necessary.
-  aStyleChanging = false;
-
   // If multiple animations specify behavior for the same property the
   // animation with the *highest* composite order wins.
   // As a result, we iterate from last animation to first and, if a
@@ -396,8 +390,7 @@ EffectCompositor::ComposeAnimationRule(dom::Element* aElement,
   nsCSSPropertySet properties;
 
   for (KeyframeEffectReadOnly* effect : Reversed(sortedEffectList)) {
-    effect->GetAnimation()->ComposeStyle(animationRule, properties,
-                                         aStyleChanging);
+    effect->GetAnimation()->ComposeStyle(animationRule, properties);
   }
 
   effects->UpdateAnimationRuleRefreshTime(aCascadeLevel, aRefreshTime);

dom/animation/EffectCompositor.h

@@ -102,8 +102,7 @@ public:
   // no work is done.
   void MaybeUpdateAnimationRule(dom::Element* aElement,
                                 nsCSSPseudoElements::Type aPseudoType,
-                                CascadeLevel aCascadeLevel,
-                                bool& aStyleChanging);
+                                CascadeLevel aCascadeLevel);
 
   // FIXME: Temporary method until we move FlushAnimations here.
   bool HasThrottledAnimations(dom::Element* aElement,
@@ -161,8 +160,7 @@ private:
   static void ComposeAnimationRule(dom::Element* aElement,
                                    nsCSSPseudoElements::Type aPseudoType,
                                    CascadeLevel aCascadeLevel,
-                                   TimeStamp aRefreshTime,
-                                   bool& aStyleChanging);
+                                   TimeStamp aRefreshTime);
 
   static dom::Element* GetElementToRestyle(dom::Element* aElement,
                                            nsCSSPseudoElements::Type

layout/style/AnimationCommon.cpp

@@ -428,10 +428,6 @@ AnimationCollection::EnsureStyleRuleFor()
     return;
   }
 
-  if (!mStyleChanging) {
-    return;
-  }
-
   // Update cascade results before updating the style rule, since the
   // cascade results can influence the style rule.
   nsStyleContext* styleContext = nullptr;
@@ -454,8 +450,7 @@ AnimationCollection::EnsureStyleRuleFor()
     EffectCompositor::CascadeLevel::Transitions;
   presContext->EffectCompositor()->MaybeUpdateAnimationRule(mElement,
                                                             PseudoElementType(),
-                                                            cascadeLevel,
-                                                            mStyleChanging);
+                                                            cascadeLevel);
 }
 
 void
@@ -482,7 +477,6 @@ AnimationCollection::RequestRestyle(EffectCompositor::RestyleType aRestyleType)
   // Steps for RestyleType::Layer:
 
   if (aRestyleType == EffectCompositor::RestyleType::Layer) {
-    mStyleChanging = true;
 
     // Prompt layers to re-sync their animations.
     presContext->ClearLastStyleUpdateForAllAnimations();

layout/style/AnimationCommon.h

@@ -144,7 +144,6 @@ struct AnimationCollection : public LinkedListElement<AnimationCollection>
     , mElementProperty(aElementProperty)
     , mManager(aManager)
     , mCheckGeneration(0)
-    , mStyleChanging(true)
     , mHasPendingAnimationRestyle(false)
 #ifdef DEBUG
     , mCalledPropertyDtor(false)
@@ -253,11 +252,6 @@ public:
   // Update mCheckGeneration to RestyleManager's count
   void UpdateCheckGeneration(nsPresContext* aPresContext);
 
-  // False when we know that our current animation rule is valid
-  // indefinitely into the future (because all of our animations are
-  // either completed or paused).  May be invalidated by a style change.
-  bool mStyleChanging;
-
 private:
   // Whether or not we have already posted for animation restyle.
   // This is used to avoid making redundant requests and is reset each time

layout/style/nsAnimationManager.cpp

@@ -538,7 +538,6 @@ nsAnimationManager::CheckAnimationRule(nsStyleContext* aStyleContext,
     }
   }
   collection->mAnimations.SwapElements(newAnimations);
-  collection->mStyleChanging = true;
 
   // Cancel removed animations
   for (size_t newAnimIdx = newAnimations.Length(); newAnimIdx-- != 0; ) {

layout/style/nsTransitionManager.cpp

@@ -489,7 +489,6 @@ nsTransitionManager::StyleContextChanged(dom::Element *aElement,
                                            newStyleContext);
 
     collection->UpdateCheckGeneration(mPresContext);
-    collection->mStyleChanging = true;
     collection->EnsureStyleRuleFor();
   }