CC Animation: Introduce some dirty flags to optimize PushProperties on commit

cc/animation/element_animations.cc

Index: cc/animation/element_animations.cc
diff --git a/cc/animation/element_animations.cc b/cc/animation/element_animations.cc
index 80823d226b1b3a4893705570d3a4ecfaafbdf0d4..0c6aa877f6016dfefa16b6d615a9860ccead20a6 100644
--- a/cc/animation/element_animations.cc
+++ b/cc/animation/element_animations.cc
@@ -33,7 +33,8 @@ ElementAnimations::ElementAnimations()
       has_element_in_active_list_(false),
       has_element_in_pending_list_(false),
       needs_to_start_animations_(false),
-      scroll_offset_animation_was_interrupted_(false) {}
+      scroll_offset_animation_was_interrupted_(false),
+      needs_push_properties_(false) {}
 
 ElementAnimations::~ElementAnimations() {}
 
@@ -122,9 +123,18 @@ bool ElementAnimations::IsEmpty() const {
   return !players_list_->might_have_observers();
 }
 
+void ElementAnimations::SetNeedsPushProperties() {
+  needs_push_properties_ = true;
+}
+
 void ElementAnimations::PushPropertiesTo(
     scoped_refptr<ElementAnimations> element_animations_impl) {
   DCHECK_NE(this, element_animations_impl);
+
+  if (!needs_push_properties_)
+    return;
+  needs_push_properties_ = false;
+
   if (!has_any_animation() && !element_animations_impl->has_any_animation())
     return;
   MarkAbortedAnimationsForDeletion(element_animations_impl.get());
@@ -886,7 +896,7 @@ void ElementAnimations::MarkAnimationsForDeletion(
     }
   }
   if (marked_animations_for_deletions)
-    NotifyClientAnimationWaitingForDeletion();
+    NotifyPlayersAnimationWaitingForDeletion();
 }
 
 void ElementAnimations::MarkAbortedAnimationsForDeletion(
@@ -1065,10 +1075,6 @@ void ElementAnimations::NotifyClientScrollOffsetAnimated(
     OnScrollOffsetAnimated(ElementListType::PENDING, scroll_offset);
 }
 
-void ElementAnimations::NotifyClientAnimationWaitingForDeletion() {
-  OnAnimationWaitingForDeletion();
-}
-
 void ElementAnimations::NotifyClientAnimationChanged(
     TargetProperty::Type property,
     ElementListType list_type,
@@ -1388,13 +1394,6 @@ void ElementAnimations::OnScrollOffsetAnimated(
       element_id(), list_type, scroll_offset);
 }
 
-void ElementAnimations::OnAnimationWaitingForDeletion() {
-  // TODO(loyso): Invalidate AnimationHost::SetNeedsPushProperties here.
-  // But we always do PushProperties in AnimationHost for now. crbug.com/604280
-  DCHECK(animation_host());
-  animation_host()->OnAnimationWaitingForDeletion();
-}
-
 void ElementAnimations::IsAnimatingChanged(ElementListType list_type,
                                            TargetProperty::Type property,
                                            AnimationChangeType change_type,
@@ -1461,6 +1460,13 @@ void ElementAnimations::NotifyPlayersAnimationAborted(
     player->NotifyAnimationAborted(monotonic_time, target_property, group);
 }
 
+void ElementAnimations::NotifyPlayersAnimationWaitingForDeletion() {
+  ElementAnimations::PlayersList::Iterator it(players_list_.get());
+  AnimationPlayer* player;
+  while ((player = it.GetNext()) != nullptr)
+    player->NotifyAnimationWaitingForDeletion();
+}
+
 void ElementAnimations::NotifyPlayersAnimationTakeover(
     base::TimeTicks monotonic_time,
     TargetProperty::Type target_property,