Bug 1123523 - Part 3: Store a flag on AnimationPlayer for whether it is exposed by Element.getAnimationPlayers(). r=birtles

dom/animation/AnimationPlayer.cpp

@@ -231,6 +231,7 @@ AnimationPlayer::SetSource(Animation* aSource)
   if (mSource) {
     mSource->SetParentTime(GetCurrentTime());
   }
+  UpdateRelevance();
 }
 
 void
@@ -316,6 +317,8 @@ AnimationPlayer::Cancel()
 
   mHoldTime.SetNull();
   mStartTime.SetNull();
+
+  UpdateSourceContent();
 }
 
 bool
@@ -329,6 +332,12 @@ AnimationPlayer::IsRunning() const
   return computedTiming.mPhase == ComputedTiming::AnimationPhase_Active;
 }
 
+void
+AnimationPlayer::UpdateRelevance()
+{
+  mIsRelevant = HasCurrentSource() || HasInEffectSource();
+}
+
 bool
 AnimationPlayer::CanThrottle() const
 {
@@ -459,6 +468,7 @@ AnimationPlayer::UpdateSourceContent()
 {
   if (mSource) {
     mSource->SetParentTime(GetCurrentTime());
+    UpdateRelevance();
   }
 }
 

dom/animation/AnimationPlayer.h

@@ -56,6 +56,7 @@ public:
     , mIsPending(false)
     , mIsRunningOnCompositor(false)
     , mIsPreviousStateFinished(false)
+    , mIsRelevant(false)
   {
   }
 
@@ -191,6 +192,9 @@ public:
     return GetSource() && GetSource()->IsInEffect();
   }
 
+  bool IsRelevant() const { return mIsRelevant; }
+  void UpdateRelevance();
+
   void SetIsRunningOnCompositor() { mIsRunningOnCompositor = true; }
   void ClearIsRunningOnCompositor() { mIsRunningOnCompositor = false; }
 
@@ -256,6 +260,9 @@ protected:
   // probably remove this and check if the promise has been settled yet
   // or not instead.
   bool mIsPreviousStateFinished; // Spec calls this "previous finished state"
+  // Indicates that the player should be exposed in an element's
+  // getAnimationPlayers() list.
+  bool mIsRelevant;
 };
 
 } // namespace dom

dom/base/Element.cpp

@@ -3188,7 +3188,7 @@ Element::GetAnimationPlayers(nsTArray<nsRefPtr<AnimationPlayer> >& aPlayers)
          playerIdx < collection->mPlayers.Length();
          playerIdx++) {
       AnimationPlayer* player = collection->mPlayers[playerIdx];
-      if (player->HasCurrentSource() || player->HasInEffectSource()) {
+      if (player->IsRelevant()) {
         aPlayers.AppendElement(player);
       }
     }

layout/style/nsAnimationManager.cpp

@@ -350,6 +350,10 @@ nsAnimationManager::CheckAnimationRule(nsStyleContext* aStyleContext,
         newPlayer = nullptr;
         newPlayers.ReplaceElementAt(newIdx, oldPlayer);
         collection->mPlayers.RemoveElementAt(oldIdx);
+
+        // We've touched the old animation's timing properties, so this
+        // could update the old player's relevance.
+        oldPlayer->UpdateRelevance();
       }
     }
   } else {