CC Animation: Move animations_ from ElementAnimations to AnimationPlayer.

cc/animation/animation_player.cc

Index: cc/animation/animation_player.cc
diff --git a/cc/animation/animation_player.cc b/cc/animation/animation_player.cc
index bef51a07390a6c1f822681804232856ad22c3950..de5801e74f423e2638bb7402114a7811deec5cc3 100644
--- a/cc/animation/animation_player.cc
+++ b/cc/animation/animation_player.cc
@@ -9,7 +9,7 @@
 #include "cc/animation/animation_delegate.h"
 #include "cc/animation/animation_host.h"
 #include "cc/animation/animation_timeline.h"
-#include "cc/animation/element_animations.h"
+#include "cc/animation/scroll_offset_animation_curve.h"
 
 namespace cc {
 
@@ -23,7 +23,8 @@ AnimationPlayer::AnimationPlayer(int id)
       element_animations_(),
       animation_delegate_(),
       id_(id),
-      needs_push_properties_(false) {
+      needs_push_properties_(false),
+      needs_to_start_animations_(false) {
   DCHECK(id_);
 }
 
@@ -104,80 +105,141 @@ void AnimationPlayer::BindElementAnimations() {
       animation_host_->GetElementAnimationsForElementId(element_id_);
   DCHECK(element_animations_);
 
-  // Pass all accumulated animations to ElementAnimations.
   for (auto& animation : animations_)
-    element_animations_->AddAnimation(std::move(animation));
+    AnimationAddedForProperty(animation->target_property());
 
-  if (!animations_.empty())
-    SetNeedsCommit();
   SetNeedsPushProperties();
-
-  animations_.clear();
 }
 
 void AnimationPlayer::UnbindElementAnimations() {
   SetNeedsPushProperties();
-
   element_animations_ = nullptr;
-  DCHECK(animations_.empty());
 }
 
 void AnimationPlayer::AddAnimation(std::unique_ptr<Animation> animation) {
   DCHECK(animation->target_property() != TargetProperty::SCROLL_OFFSET ||
          (animation_host_ && animation_host_->SupportsScrollAnimations()));
+  DCHECK(!animation->is_impl_only() ||
+         animation->target_property() == TargetProperty::SCROLL_OFFSET);
 
+  TargetProperty::Type target_property = animation->target_property();
+  animations_.push_back(std::move(animation));
   if (element_animations_) {
-    element_animations_->AddAnimation(std::move(animation));
-    SetNeedsCommit();
+    AnimationAddedForProperty(target_property);
     SetNeedsPushProperties();
-  } else {
-    animations_.push_back(std::move(animation));
   }
 }
 
-void AnimationPlayer::PauseAnimation(int animation_id, double time_offset) {
+void AnimationPlayer::AnimationAddedForProperty(
+    TargetProperty::Type target_property) {
   DCHECK(element_animations_);
-  element_animations_->PauseAnimation(
-      animation_id, base::TimeDelta::FromSecondsD(time_offset));
+
   SetNeedsCommit();
-  SetNeedsPushProperties();
+  needs_to_start_animations_ = true;
+
+  element_animations_->UpdateActivationNormal();
+  element_animations_->UpdateClientAnimationState(target_property);
+}
+
+void AnimationPlayer::PauseAnimation(int animation_id, double time_offset) {
+  const base::TimeDelta time_delta = base::TimeDelta::FromSecondsD(time_offset);
+
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->id() == animation_id) {
+      animations_[i]->SetRunState(Animation::PAUSED,
+                                  time_delta + animations_[i]->start_time() +
+                                      animations_[i]->time_offset());
+    }
+  }
+
+  if (element_animations_) {
+    SetNeedsCommit();
+    SetNeedsPushProperties();
+  }
 }
 
 void AnimationPlayer::RemoveAnimation(int animation_id) {
+  bool removed_transform_animation = false;
+  bool removed_opacity_animation = false;
+  bool removed_filter_animation = false;
+  // Since we want to use the animations that we're going to remove, we need to
+  // use a stable_parition here instead of remove_if. Remove_if leaves the
+  // removed items in an unspecified state.
+  auto animations_to_remove = std::stable_partition(
+      animations_.begin(), animations_.end(),
+      [animation_id](const std::unique_ptr<Animation>& animation) {
+        return animation->id() != animation_id;
+      });
+  for (auto it = animations_to_remove; it != animations_.end(); ++it) {
+    if ((*it)->target_property() == TargetProperty::SCROLL_OFFSET) {
+      if (element_animations_)
+        element_animations_->SetScrollOffsetAnimationWasInterrupted();
+    } else if ((*it)->target_property() == TargetProperty::TRANSFORM &&
+               !(*it)->is_finished()) {
+      removed_transform_animation = true;
+    } else if ((*it)->target_property() == TargetProperty::OPACITY &&
+               !(*it)->is_finished()) {
+      removed_opacity_animation = true;
+    } else if ((*it)->target_property() == TargetProperty::FILTER &&
+               !(*it)->is_finished()) {
+      removed_filter_animation = true;
+    }
+  }
+
+  animations_.erase(animations_to_remove, animations_.end());
+
   if (element_animations_) {
-    element_animations_->RemoveAnimation(animation_id);
+    element_animations_->UpdateActivationNormal();
+    element_animations_->UpdateClientAnimationState(removed_transform_animation,
+                                                    removed_opacity_animation,
+                                                    removed_filter_animation);
     SetNeedsCommit();
     SetNeedsPushProperties();
-  } else {
-    auto animations_to_remove = std::remove_if(
-        animations_.begin(), animations_.end(),
-        [animation_id](const std::unique_ptr<Animation>& animation) {
-          return animation->id() == animation_id;
-        });
-    animations_.erase(animations_to_remove, animations_.end());
   }
 }
 
 void AnimationPlayer::AbortAnimation(int animation_id) {
-  DCHECK(element_animations_);
-  element_animations_->AbortAnimation(animation_id);
-  SetNeedsCommit();
-  SetNeedsPushProperties();
+  if (Animation* animation = GetAnimationById(animation_id)) {
+    if (!animation->is_finished()) {
+      animation->SetRunState(Animation::ABORTED, last_tick_time_);
+      if (element_animations_)
+        element_animations_->UpdateClientAnimationState(
+            animation->target_property());
+    }
+  }
+
+  if (element_animations_) {
+    SetNeedsCommit();
+    SetNeedsPushProperties();
+  }
 }
 
 void AnimationPlayer::AbortAnimations(TargetProperty::Type target_property,
                                       bool needs_completion) {
+  if (needs_completion)
+    DCHECK(target_property == TargetProperty::SCROLL_OFFSET);
+
+  bool aborted_animation = false;
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->target_property() == target_property &&
+        !animations_[i]->is_finished()) {
+      // Currently only impl-only scroll offset animations can be completed on
+      // the main thread.
+      if (needs_completion && animations_[i]->is_impl_only()) {
+        animations_[i]->SetRunState(Animation::ABORTED_BUT_NEEDS_COMPLETION,
+                                    last_tick_time_);
+      } else {
+        animations_[i]->SetRunState(Animation::ABORTED, last_tick_time_);
+      }
+      aborted_animation = true;
+    }
+  }
+
   if (element_animations_) {
-    element_animations_->AbortAnimations(target_property, needs_completion);
+    if (aborted_animation)
+      element_animations_->UpdateClientAnimationState(target_property);
     SetNeedsCommit();
     SetNeedsPushProperties();
-  } else {
-    auto animations_to_remove = std::remove_if(
-        animations_.begin(), animations_.end(),
-        [target_property](const std::unique_ptr<Animation>& animation) {
-          return animation->target_property() == target_property;
-        });
-    animations_.erase(animations_to_remove, animations_.end());
   }
 }
 
@@ -186,59 +248,110 @@ void AnimationPlayer::PushPropertiesTo(AnimationPlayer* player_impl) {
     return;
   needs_push_properties_ = false;
 
+  // Create or destroy ElementAnimations.
   if (element_id_ != player_impl->element_id()) {
     if (player_impl->element_id())
       player_impl->DetachElement();
     if (element_id_)
       player_impl->AttachElement(element_id_);
   }
+
+  if (!has_any_animation() && !player_impl->has_any_animation())
+    return;
+
+  MarkAbortedAnimationsForDeletion(player_impl);
+  PurgeAnimationsMarkedForDeletion();
+  PushNewAnimationsToImplThread(player_impl);
+
+  // Remove finished impl side animations only after pushing,
+  // and only after the animations are deleted on the main thread
+  // this insures we will never push an animation twice.
+  RemoveAnimationsCompletedOnMainThread(player_impl);
+
+  PushPropertiesToImplThread(player_impl);
 }
 
-void AnimationPlayer::NotifyAnimationStarted(
-    base::TimeTicks monotonic_time,
-    TargetProperty::Type target_property,
-    int group) {
-  if (animation_delegate_)
-    animation_delegate_->NotifyAnimationStarted(monotonic_time, target_property,
-                                                group);
+bool AnimationPlayer::NotifyAnimationStarted(const AnimationEvent& event) {
+  DCHECK(!event.is_impl_only);
+
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->group() == event.group_id &&
+        animations_[i]->target_property() == event.target_property &&
+        animations_[i]->needs_synchronized_start_time()) {
+      animations_[i]->set_needs_synchronized_start_time(false);
+      if (!animations_[i]->has_set_start_time())
+        animations_[i]->set_start_time(event.monotonic_time);
+
+      if (animation_delegate_) {
+        animation_delegate_->NotifyAnimationStarted(
+            event.monotonic_time, event.target_property, event.group_id);
+      }
+      return true;
+    }
+  }
+
+  return false;
 }
 
-void AnimationPlayer::NotifyAnimationFinished(
-    base::TimeTicks monotonic_time,
-    TargetProperty::Type target_property,
-    int group) {
-  if (animation_delegate_)
-    animation_delegate_->NotifyAnimationFinished(monotonic_time,
-                                                 target_property, group);
+bool AnimationPlayer::NotifyAnimationFinished(const AnimationEvent& event) {
+  DCHECK(!event.is_impl_only);
+
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->group() == event.group_id &&
+        animations_[i]->target_property() == event.target_property) {
+      animations_[i]->set_received_finished_event(true);
+
+      if (animation_delegate_) {
+        animation_delegate_->NotifyAnimationFinished(
+            event.monotonic_time, event.target_property, event.group_id);
+      }
+      return true;
+    }
+  }
+
+  return false;
 }
 
-void AnimationPlayer::NotifyAnimationAborted(
-    base::TimeTicks monotonic_time,
+bool AnimationPlayer::NotifyAnimationFinishedForTesting(
     TargetProperty::Type target_property,
-    int group) {
-  if (animation_delegate_)
-    animation_delegate_->NotifyAnimationAborted(monotonic_time, target_property,
-                                                group);
+    int group_id) {
+  AnimationEvent event(AnimationEvent::FINISHED, element_id_, group_id,
+                       target_property, base::TimeTicks());
+  return NotifyAnimationFinished(event);
 }
 
-void AnimationPlayer::NotifyAnimationWaitingForDeletion() {
-  // We need to purge animations marked for deletion.
-  SetNeedsPushProperties();
+bool AnimationPlayer::NotifyAnimationAborted(const AnimationEvent& event) {
+  DCHECK(!event.is_impl_only);
+
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->group() == event.group_id &&
+        animations_[i]->target_property() == event.target_property) {
+      animations_[i]->SetRunState(Animation::ABORTED, event.monotonic_time);
+      animations_[i]->set_received_finished_event(true);
+      if (animation_delegate_) {
+        animation_delegate_->NotifyAnimationAborted(
+            event.monotonic_time, event.target_property, event.group_id);
+      }
+      return true;
+    }
+  }
+
+  return false;
 }
 
-void AnimationPlayer::NotifyAnimationTakeover(
-    base::TimeTicks monotonic_time,
-    TargetProperty::Type target_property,
-    double animation_start_time,
-    std::unique_ptr<AnimationCurve> curve) {
+void AnimationPlayer::NotifyAnimationTakeover(const AnimationEvent& event) {
+  DCHECK(!event.is_impl_only);
+  DCHECK(event.target_property == TargetProperty::SCROLL_OFFSET);
+
   // We need to purge animations marked for deletion on CT.
   SetNeedsPushProperties();
 
   if (animation_delegate_) {
-    DCHECK(curve);
+    DCHECK(event.curve);
+    std::unique_ptr<AnimationCurve> animation_curve = event.curve->Clone();
     animation_delegate_->NotifyAnimationTakeover(
-        monotonic_time, target_property, animation_start_time,
-        std::move(curve));
+        event.monotonic_time, event.target_property, event.animation_start_time,
+        std::move(animation_curve));
   }
 }
 
@@ -257,4 +370,780 @@ void AnimationPlayer::SetNeedsPushProperties() {
   element_animations_->SetNeedsPushProperties();
 }
 
+bool AnimationPlayer::HasActiveAnimation() const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (!animations_[i]->is_finished())
+      return true;
+  }
+  return false;
+}
+
+bool AnimationPlayer::HasNonDeletedAnimation() const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->run_state() != Animation::WAITING_FOR_DELETION)
+      return true;
+  }
+
+  return false;
+}
+
+void AnimationPlayer::StartAnimations(base::TimeTicks monotonic_time) {
+  DCHECK(needs_to_start_animations_);
+  needs_to_start_animations_ = false;
+  // First collect running properties affecting each type of element.
+  TargetProperties blocked_properties_for_active_elements;
+  TargetProperties blocked_properties_for_pending_elements;
+  std::vector<size_t> animations_waiting_for_target;
+
+  animations_waiting_for_target.reserve(animations_.size());
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->run_state() == Animation::STARTING ||
+        animations_[i]->run_state() == Animation::RUNNING) {
+      if (animations_[i]->affects_active_elements()) {
+        blocked_properties_for_active_elements[animations_[i]
+                                                   ->target_property()] = true;
+      }
+      if (animations_[i]->affects_pending_elements()) {
+        blocked_properties_for_pending_elements[animations_[i]
+                                                    ->target_property()] = true;
+      }
+    } else if (animations_[i]->run_state() ==
+               Animation::WAITING_FOR_TARGET_AVAILABILITY) {
+      animations_waiting_for_target.push_back(i);
+    }
+  }
+
+  for (size_t i = 0; i < animations_waiting_for_target.size(); ++i) {
+    // Collect all properties for animations with the same group id (they
+    // should all also be in the list of animations).
+    size_t animation_index = animations_waiting_for_target[i];
+    Animation* animation_waiting_for_target =
+        animations_[animation_index].get();
+    // Check for the run state again even though the animation was waiting
+    // for target because it might have changed the run state while handling
+    // previous animation in this loop (if they belong to same group).
+    if (animation_waiting_for_target->run_state() ==
+        Animation::WAITING_FOR_TARGET_AVAILABILITY) {
+      TargetProperties enqueued_properties;
+      bool affects_active_elements =
+          animation_waiting_for_target->affects_active_elements();
+      bool affects_pending_elements =
+          animation_waiting_for_target->affects_pending_elements();
+      enqueued_properties[animation_waiting_for_target->target_property()] =
+          true;
+      for (size_t j = animation_index + 1; j < animations_.size(); ++j) {
+        if (animation_waiting_for_target->group() == animations_[j]->group()) {
+          enqueued_properties[animations_[j]->target_property()] = true;
+          affects_active_elements |= animations_[j]->affects_active_elements();
+          affects_pending_elements |=
+              animations_[j]->affects_pending_elements();
+        }
+      }
+
+      // Check to see if intersection of the list of properties affected by
+      // the group and the list of currently blocked properties is null, taking
+      // into account the type(s) of elements affected by the group. In any
+      // case, the group's target properties need to be added to the lists of
+      // blocked properties.
+      bool null_intersection = true;
+      static_assert(TargetProperty::FIRST_TARGET_PROPERTY == 0,
+                    "TargetProperty must be 0-based enum");
+      for (int property = TargetProperty::FIRST_TARGET_PROPERTY;
+           property <= TargetProperty::LAST_TARGET_PROPERTY; ++property) {
+        if (enqueued_properties[property]) {
+          if (affects_active_elements) {
+            if (blocked_properties_for_active_elements[property])
+              null_intersection = false;
+            else
+              blocked_properties_for_active_elements[property] = true;
+          }
+          if (affects_pending_elements) {
+            if (blocked_properties_for_pending_elements[property])
+              null_intersection = false;
+            else
+              blocked_properties_for_pending_elements[property] = true;
+          }
+        }
+      }
+
+      // If the intersection is null, then we are free to start the animations
+      // in the group.
+      if (null_intersection) {
+        animation_waiting_for_target->SetRunState(Animation::STARTING,
+                                                  monotonic_time);
+        for (size_t j = animation_index + 1; j < animations_.size(); ++j) {
+          if (animation_waiting_for_target->group() ==
+              animations_[j]->group()) {
+            animations_[j]->SetRunState(Animation::STARTING, monotonic_time);
+          }
+        }
+      } else {
+        needs_to_start_animations_ = true;
+      }
+    }
+  }
+}
+
+void AnimationPlayer::PromoteStartedAnimations(base::TimeTicks monotonic_time,
+                                               AnimationEvents* events) {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->run_state() == Animation::STARTING &&
+        animations_[i]->affects_active_elements()) {
+      animations_[i]->SetRunState(Animation::RUNNING, monotonic_time);
+      if (!animations_[i]->has_set_start_time() &&
+          !animations_[i]->needs_synchronized_start_time())
+        animations_[i]->set_start_time(monotonic_time);
+      if (events) {
+        base::TimeTicks start_time;
+        if (animations_[i]->has_set_start_time())
+          start_time = animations_[i]->start_time();
+        else
+          start_time = monotonic_time;
+        AnimationEvent started_event(
+            AnimationEvent::STARTED, element_id_, animations_[i]->group(),
+            animations_[i]->target_property(), start_time);
+        started_event.is_impl_only = animations_[i]->is_impl_only();
+        if (started_event.is_impl_only) {
+          // Notify delegate directly, do not record the event.
+          if (animation_delegate_) {
+            animation_delegate_->NotifyAnimationStarted(
+                started_event.monotonic_time, started_event.target_property,
+                started_event.group_id);
+          }
+        } else {
+          events->events_.push_back(started_event);
+        }
+      }
+    }
+  }
+}
+
+void AnimationPlayer::MarkAnimationsForDeletion(base::TimeTicks monotonic_time,
+                                                AnimationEvents* events) {
+  bool marked_animations_for_deletions = false;
+  std::vector<size_t> animations_with_same_group_id;
+
+  animations_with_same_group_id.reserve(animations_.size());
+  // Non-aborted animations are marked for deletion after a corresponding
+  // AnimationEvent::FINISHED event is sent or received. This means that if
+  // we don't have an events vector, we must ensure that non-aborted animations
+  // have received a finished event before marking them for deletion.
+  for (size_t i = 0; i < animations_.size(); i++) {
+    int group_id = animations_[i]->group();
+    if (animations_[i]->run_state() == Animation::ABORTED) {
+      if (events && !animations_[i]->is_impl_only()) {
+        AnimationEvent aborted_event(
+            AnimationEvent::ABORTED, element_id_, group_id,
+            animations_[i]->target_property(), monotonic_time);
+        events->events_.push_back(aborted_event);
+      }
+      // If on the compositor or on the main thread and received finish event,
+      // animation can be marked for deletion.
+      if (events || animations_[i]->received_finished_event()) {
+        animations_[i]->SetRunState(Animation::WAITING_FOR_DELETION,
+                                    monotonic_time);
+        marked_animations_for_deletions = true;
+      }
+      continue;
+    }
+
+    // If running on the compositor and need to complete an aborted animation
+    // on the main thread.
+    if (events &&
+        animations_[i]->run_state() ==
+            Animation::ABORTED_BUT_NEEDS_COMPLETION) {
+      AnimationEvent aborted_event(AnimationEvent::TAKEOVER, element_id_,
+                                   group_id, animations_[i]->target_property(),
+                                   monotonic_time);
+      aborted_event.animation_start_time =
+          (animations_[i]->start_time() - base::TimeTicks()).InSecondsF();
+      const ScrollOffsetAnimationCurve* scroll_offset_animation_curve =
+          animations_[i]->curve()->ToScrollOffsetAnimationCurve();
+      aborted_event.curve = scroll_offset_animation_curve->Clone();
+      // Notify the compositor that the animation is finished.
+      if (animation_delegate_) {
+        animation_delegate_->NotifyAnimationFinished(
+            aborted_event.monotonic_time, aborted_event.target_property,
+            aborted_event.group_id);
+      }
+      // Notify main thread.
+      events->events_.push_back(aborted_event);
+
+      // Remove the animation from the compositor.
+      animations_[i]->SetRunState(Animation::WAITING_FOR_DELETION,
+                                  monotonic_time);
+      marked_animations_for_deletions = true;
+      continue;
+    }
+
+    bool all_anims_with_same_id_are_finished = false;
+
+    // Since deleting an animation on the main thread leads to its deletion
+    // on the impl thread, we only mark a FINISHED main thread animation for
+    // deletion once it has received a FINISHED event from the impl thread.
+    bool animation_i_will_send_or_has_received_finish_event =
+        animations_[i]->is_controlling_instance() ||
+        animations_[i]->is_impl_only() ||
+        animations_[i]->received_finished_event();
+    // If an animation is finished, and not already marked for deletion,
+    // find out if all other animations in the same group are also finished.
+    if (animations_[i]->run_state() == Animation::FINISHED &&
+        animation_i_will_send_or_has_received_finish_event) {
+      // Clear the animations_with_same_group_id if it was added for
+      // the previous animation's iteration.
+      if (animations_with_same_group_id.size() > 0)
+        animations_with_same_group_id.clear();
+      all_anims_with_same_id_are_finished = true;
+      for (size_t j = 0; j < animations_.size(); ++j) {
+        bool animation_j_will_send_or_has_received_finish_event =
+            animations_[j]->is_controlling_instance() ||
+            animations_[j]->is_impl_only() ||
+            animations_[j]->received_finished_event();
+        if (group_id == animations_[j]->group()) {
+          if (!animations_[j]->is_finished() ||
+              (animations_[j]->run_state() == Animation::FINISHED &&
+               !animation_j_will_send_or_has_received_finish_event)) {
+            all_anims_with_same_id_are_finished = false;
+            break;
+          } else if (j >= i &&
+                     animations_[j]->run_state() != Animation::ABORTED) {
+            // Mark down the animations which belong to the same group
+            // and is not yet aborted. If this current iteration finds that all
+            // animations with same ID are finished, then the marked
+            // animations below will be set to WAITING_FOR_DELETION in next
+            // iteration.
+            animations_with_same_group_id.push_back(j);
+          }
+        }
+      }
+    }
+    if (all_anims_with_same_id_are_finished) {
+      // We now need to remove all animations with the same group id as
+      // group_id (and send along animation finished notifications, if
+      // necessary).
+      for (size_t j = 0; j < animations_with_same_group_id.size(); j++) {
+        size_t animation_index = animations_with_same_group_id[j];
+        if (events) {
+          AnimationEvent finished_event(
+              AnimationEvent::FINISHED, element_id_,
+              animations_[animation_index]->group(),
+              animations_[animation_index]->target_property(), monotonic_time);
+          finished_event.is_impl_only =
+              animations_[animation_index]->is_impl_only();
+          if (finished_event.is_impl_only) {
+            // Notify delegate directly, do not record the event.
+            if (animation_delegate_) {
+              animation_delegate_->NotifyAnimationFinished(
+                  finished_event.monotonic_time, finished_event.target_property,
+                  finished_event.group_id);
+            }
+          } else {
+            events->events_.push_back(finished_event);
+          }
+        }
+        animations_[animation_index]->SetRunState(
+            Animation::WAITING_FOR_DELETION, monotonic_time);
+      }
+      marked_animations_for_deletions = true;
+    }
+  }
+
+  // Notify about animations waiting for deletion.
+  // We need to purge animations marked for deletion, which happens in
+  // PushProperties().
+  if (marked_animations_for_deletions)
+    SetNeedsPushProperties();
+}
+
+void AnimationPlayer::TickAnimations(base::TimeTicks monotonic_time) {
+  DCHECK(element_animations_);
+
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->run_state() == Animation::STARTING ||
+        animations_[i]->run_state() == Animation::RUNNING ||
+        animations_[i]->run_state() == Animation::PAUSED) {
+      if (!animations_[i]->InEffect(monotonic_time))
+        continue;
+
+      base::TimeDelta trimmed =
+          animations_[i]->TrimTimeToCurrentIteration(monotonic_time);
+
+      switch (animations_[i]->target_property()) {
+        case TargetProperty::TRANSFORM: {
+          const TransformAnimationCurve* transform_animation_curve =
+              animations_[i]->curve()->ToTransformAnimationCurve();
+          const gfx::Transform transform =
+              transform_animation_curve->GetValue(trimmed);
+          element_animations_->NotifyClientTransformAnimated(
+              transform, animations_[i]->affects_active_elements(),
+              animations_[i]->affects_pending_elements());
+          break;
+        }
+
+        case TargetProperty::OPACITY: {
+          const FloatAnimationCurve* float_animation_curve =
+              animations_[i]->curve()->ToFloatAnimationCurve();
+          const float opacity = std::max(
+              std::min(float_animation_curve->GetValue(trimmed), 1.0f), 0.f);
+          element_animations_->NotifyClientOpacityAnimated(
+              opacity, animations_[i]->affects_active_elements(),
+              animations_[i]->affects_pending_elements());
+          break;
+        }
+
+        case TargetProperty::FILTER: {
+          const FilterAnimationCurve* filter_animation_curve =
+              animations_[i]->curve()->ToFilterAnimationCurve();
+          const FilterOperations filter =
+              filter_animation_curve->GetValue(trimmed);
+          element_animations_->NotifyClientFilterAnimated(
+              filter, animations_[i]->affects_active_elements(),
+              animations_[i]->affects_pending_elements());
+          break;
+        }
+
+        case TargetProperty::BACKGROUND_COLOR: {
+          // Not yet implemented.
+          break;
+        }
+
+        case TargetProperty::SCROLL_OFFSET: {
+          const ScrollOffsetAnimationCurve* scroll_offset_animation_curve =
+              animations_[i]->curve()->ToScrollOffsetAnimationCurve();
+          const gfx::ScrollOffset scroll_offset =
+              scroll_offset_animation_curve->GetValue(trimmed);
+          element_animations_->NotifyClientScrollOffsetAnimated(
+              scroll_offset, animations_[i]->affects_active_elements(),
+              animations_[i]->affects_pending_elements());
+          break;
+        }
+      }
+    }
+  }
+
+  last_tick_time_ = monotonic_time;
+}
+
+void AnimationPlayer::MarkFinishedAnimations(base::TimeTicks monotonic_time) {
+  bool finished_transform_animation = false;
+  bool finished_opacity_animation = false;
+  bool finished_filter_animation = false;
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (!animations_[i]->is_finished() &&
+        animations_[i]->IsFinishedAt(monotonic_time)) {
+      animations_[i]->SetRunState(Animation::FINISHED, monotonic_time);
+      if (animations_[i]->target_property() == TargetProperty::TRANSFORM)
+        finished_transform_animation = true;
+      else if (animations_[i]->target_property() == TargetProperty::OPACITY)
+        finished_opacity_animation = true;
+      else if (animations_[i]->target_property() == TargetProperty::FILTER)
+        finished_filter_animation = true;
+    }
+  }
+
+  DCHECK(element_animations_);
+  element_animations_->UpdateClientAnimationState(finished_transform_animation,
+                                                  finished_opacity_animation,
+                                                  finished_filter_animation);
+}
+
+void AnimationPlayer::ActivateAnimations(bool* changed_transform_animation,
+                                         bool* changed_opacity_animation,
+                                         bool* changed_filter_animation) {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->affects_active_elements() !=
+        animations_[i]->affects_pending_elements()) {
+      if (animations_[i]->target_property() == TargetProperty::TRANSFORM)
+        *changed_transform_animation = true;
+      else if (animations_[i]->target_property() == TargetProperty::OPACITY)
+        *changed_opacity_animation = true;
+      else if (animations_[i]->target_property() == TargetProperty::FILTER)
+        *changed_filter_animation = true;
+    }
+    animations_[i]->set_affects_active_elements(
+        animations_[i]->affects_pending_elements());
+  }
+  auto affects_no_elements = [](const std::unique_ptr<Animation>& animation) {
+    return !animation->affects_active_elements() &&
+           !animation->affects_pending_elements();
+  };
+  animations_.erase(std::remove_if(animations_.begin(), animations_.end(),
+                                   affects_no_elements),
+                    animations_.end());
+}
+
+bool AnimationPlayer::HasFilterAnimationThatInflatesBounds() const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (!animations_[i]->is_finished() &&
+        animations_[i]->target_property() == TargetProperty::FILTER &&
+        animations_[i]
+            ->curve()
+            ->ToFilterAnimationCurve()
+            ->HasFilterThatMovesPixels())
+      return true;
+  }
+
+  return false;
+}
+
+bool AnimationPlayer::HasTransformAnimationThatInflatesBounds() const {
+  return IsCurrentlyAnimatingProperty(TargetProperty::TRANSFORM,
+                                      ElementListType::ACTIVE) ||
+         IsCurrentlyAnimatingProperty(TargetProperty::TRANSFORM,
+                                      ElementListType::PENDING);
+}
+
+bool AnimationPlayer::TransformAnimationBoundsForBox(const gfx::BoxF& box,
+                                                     gfx::BoxF* bounds) const {
+  DCHECK(HasTransformAnimationThatInflatesBounds())
+      << "TransformAnimationBoundsForBox will give incorrect results if there "
+      << "are no transform animations affecting bounds, non-animated transform "
+      << "is not known";
+
+  // Compute bounds based on animations for which is_finished() is false.
+  // Do nothing if there are no such animations; in this case, it is assumed
+  // that callers will take care of computing bounds based on the owning layer's
+  // actual transform.
+  *bounds = gfx::BoxF();
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    gfx::BoxF animation_bounds;
+    bool success =
+        transform_animation_curve->AnimatedBoundsForBox(box, &animation_bounds);
+    if (!success)
+      return false;
+    bounds->Union(animation_bounds);
+  }
+
+  return true;
+}
+
+bool AnimationPlayer::HasAnimationThatAffectsScale() const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    if (transform_animation_curve->AffectsScale())
+      return true;
+  }
+
+  return false;
+}
+
+bool AnimationPlayer::HasOnlyTranslationTransforms(
+    ElementListType list_type) const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    if ((list_type == ElementListType::ACTIVE &&
+         !animations_[i]->affects_active_elements()) ||
+        (list_type == ElementListType::PENDING &&
+         !animations_[i]->affects_pending_elements()))
+      continue;
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    if (!transform_animation_curve->IsTranslation())
+      return false;
+  }
+
+  return true;
+}
+
+bool AnimationPlayer::AnimationsPreserveAxisAlignment() const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    if (!transform_animation_curve->PreservesAxisAlignment())
+      return false;
+  }
+
+  return true;
+}
+
+bool AnimationPlayer::AnimationStartScale(ElementListType list_type,
+                                          float* start_scale) const {
+  *start_scale = 0.f;
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    if ((list_type == ElementListType::ACTIVE &&
+         !animations_[i]->affects_active_elements()) ||
+        (list_type == ElementListType::PENDING &&
+         !animations_[i]->affects_pending_elements()))
+      continue;
+
+    bool forward_direction = true;
+    switch (animations_[i]->direction()) {
+      case Animation::Direction::NORMAL:
+      case Animation::Direction::ALTERNATE_NORMAL:
+        forward_direction = animations_[i]->playback_rate() >= 0.0;
+        break;
+      case Animation::Direction::REVERSE:
+      case Animation::Direction::ALTERNATE_REVERSE:
+        forward_direction = animations_[i]->playback_rate() < 0.0;
+        break;
+    }
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    float animation_start_scale = 0.f;
+    if (!transform_animation_curve->AnimationStartScale(forward_direction,
+                                                        &animation_start_scale))
+      return false;
+    *start_scale = std::max(*start_scale, animation_start_scale);
+  }
+  return true;
+}
+
+bool AnimationPlayer::MaximumTargetScale(ElementListType list_type,
+                                         float* max_scale) const {
+  *max_scale = 0.f;
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (animations_[i]->is_finished() ||
+        animations_[i]->target_property() != TargetProperty::TRANSFORM)
+      continue;
+
+    if ((list_type == ElementListType::ACTIVE &&
+         !animations_[i]->affects_active_elements()) ||
+        (list_type == ElementListType::PENDING &&
+         !animations_[i]->affects_pending_elements()))
+      continue;
+
+    bool forward_direction = true;
+    switch (animations_[i]->direction()) {
+      case Animation::Direction::NORMAL:
+      case Animation::Direction::ALTERNATE_NORMAL:
+        forward_direction = animations_[i]->playback_rate() >= 0.0;
+        break;
+      case Animation::Direction::REVERSE:
+      case Animation::Direction::ALTERNATE_REVERSE:
+        forward_direction = animations_[i]->playback_rate() < 0.0;
+        break;
+    }
+
+    const TransformAnimationCurve* transform_animation_curve =
+        animations_[i]->curve()->ToTransformAnimationCurve();
+    float animation_scale = 0.f;
+    if (!transform_animation_curve->MaximumTargetScale(forward_direction,
+                                                       &animation_scale))
+      return false;
+    *max_scale = std::max(*max_scale, animation_scale);
+  }
+
+  return true;
+}
+
+bool AnimationPlayer::IsPotentiallyAnimatingProperty(
+    TargetProperty::Type target_property,
+    ElementListType list_type) const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (!animations_[i]->is_finished() &&
+        animations_[i]->target_property() == target_property) {
+      if ((list_type == ElementListType::ACTIVE &&
+           animations_[i]->affects_active_elements()) ||
+          (list_type == ElementListType::PENDING &&
+           animations_[i]->affects_pending_elements()))
+        return true;
+    }
+  }
+  return false;
+}
+
+bool AnimationPlayer::IsCurrentlyAnimatingProperty(
+    TargetProperty::Type target_property,
+    ElementListType list_type) const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    if (!animations_[i]->is_finished() &&
+        animations_[i]->InEffect(last_tick_time_) &&
+        animations_[i]->target_property() == target_property) {
+      if ((list_type == ElementListType::ACTIVE &&
+           animations_[i]->affects_active_elements()) ||
+          (list_type == ElementListType::PENDING &&
+           animations_[i]->affects_pending_elements()))
+        return true;
+    }
+  }
+  return false;
+}
+
+bool AnimationPlayer::HasElementInActiveList() const {
+  DCHECK(element_animations_);
+  return element_animations_->has_element_in_active_list();
+}
+
+gfx::ScrollOffset AnimationPlayer::ScrollOffsetForAnimation() const {
+  DCHECK(element_animations_);
+  return element_animations_->ScrollOffsetForAnimation();
+}
+
+Animation* AnimationPlayer::GetAnimation(
+    TargetProperty::Type target_property) const {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    size_t index = animations_.size() - i - 1;
+    if (animations_[index]->target_property() == target_property)
+      return animations_[index].get();
+  }
+  return nullptr;
+}
+
+Animation* AnimationPlayer::GetAnimationById(int animation_id) const {
+  for (size_t i = 0; i < animations_.size(); ++i)
+    if (animations_[i]->id() == animation_id)
+      return animations_[i].get();
+  return nullptr;
+}
+
+void AnimationPlayer::MarkAbortedAnimationsForDeletion(
+    AnimationPlayer* animation_player_impl) const {
+  bool aborted_transform_animation = false;
+  bool aborted_opacity_animation = false;
+  bool aborted_filter_animation = false;
+  auto& animations_impl = animation_player_impl->animations_;
+  for (const auto& animation_impl : animations_impl) {
+    // If the animation has been aborted on the main thread, mark it for
+    // deletion.
+    if (Animation* animation = GetAnimationById(animation_impl->id())) {
+      if (animation->run_state() == Animation::ABORTED) {
+        animation_impl->SetRunState(Animation::WAITING_FOR_DELETION,
+                                    animation_player_impl->last_tick_time_);
+        animation->SetRunState(Animation::WAITING_FOR_DELETION,
+                               last_tick_time_);
+        if (animation_impl->target_property() == TargetProperty::TRANSFORM)
+          aborted_transform_animation = true;
+        else if (animation_impl->target_property() == TargetProperty::OPACITY)
+          aborted_opacity_animation = true;
+        else if (animation_impl->target_property() == TargetProperty::FILTER)
+          aborted_filter_animation = true;
+      }
+    }
+  }
+
+  if (element_animations_)
+    element_animations_->SetNeedsUpdateImplClientState(
+        aborted_transform_animation, aborted_opacity_animation,
+        aborted_filter_animation);
+}
+
+void AnimationPlayer::PurgeAnimationsMarkedForDeletion() {
+  animations_.erase(
+      std::remove_if(animations_.begin(), animations_.end(),
+                     [](const std::unique_ptr<Animation>& animation) {
+                       return animation->run_state() ==
+                              Animation::WAITING_FOR_DELETION;
+                     }),
+      animations_.end());
+}
+
+void AnimationPlayer::PushNewAnimationsToImplThread(
+    AnimationPlayer* animation_player_impl) const {
+  // Any new animations owned by the main thread's ElementAnimations are cloned
+  // and added to the impl thread's ElementAnimations.
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    // If the animation is already running on the impl thread, there is no
+    // need to copy it over.
+    if (animation_player_impl->GetAnimationById(animations_[i]->id()))
+      continue;
+
+    if (animations_[i]->target_property() == TargetProperty::SCROLL_OFFSET &&
+        !animations_[i]
+             ->curve()
+             ->ToScrollOffsetAnimationCurve()
+             ->HasSetInitialValue()) {
+      gfx::ScrollOffset current_scroll_offset;
+      if (animation_player_impl->HasElementInActiveList()) {
+        current_scroll_offset =
+            animation_player_impl->ScrollOffsetForAnimation();
+      } else {
+        // The owning layer isn't yet in the active tree, so the main thread
+        // scroll offset will be up to date.
+        current_scroll_offset = ScrollOffsetForAnimation();
+      }
+      animations_[i]->curve()->ToScrollOffsetAnimationCurve()->SetInitialValue(
+          current_scroll_offset);
+    }
+
+    // The new animation should be set to run as soon as possible.
+    Animation::RunState initial_run_state =
+        Animation::WAITING_FOR_TARGET_AVAILABILITY;
+    std::unique_ptr<Animation> to_add(
+        animations_[i]->CloneAndInitialize(initial_run_state));
+    DCHECK(!to_add->needs_synchronized_start_time());
+    to_add->set_affects_active_elements(false);
+    animation_player_impl->AddAnimation(std::move(to_add));
+  }
+}
+
+static bool IsCompleted(Animation* animation,
+                        const AnimationPlayer* main_thread_player) {
+  if (animation->is_impl_only()) {
+    return (animation->run_state() == Animation::WAITING_FOR_DELETION);
+  } else {
+    return !main_thread_player->GetAnimationById(animation->id());
+  }
+}
+
+void AnimationPlayer::RemoveAnimationsCompletedOnMainThread(
+    AnimationPlayer* animation_player_impl) const {
+  bool removed_transform_animation = false;
+  bool removed_opacity_animation = false;
+  bool removed_filter_animation = false;
+  // Animations removed on the main thread should no longer affect pending
+  // elements, and should stop affecting active elements after the next call
+  // to ActivateAnimations. If already WAITING_FOR_DELETION, they can be removed
+  // immediately.
+  auto& animations = animation_player_impl->animations_;
+  for (const auto& animation : animations) {
+    if (IsCompleted(animation.get(), this)) {
+      animation->set_affects_pending_elements(false);
+      if (animation->target_property() == TargetProperty::TRANSFORM)
+        removed_transform_animation = true;
+      else if (animation->target_property() == TargetProperty::OPACITY)
+        removed_opacity_animation = true;
+      else if (animation->target_property() == TargetProperty::FILTER)
+        removed_filter_animation = true;
+    }
+  }
+  auto affects_active_only_and_is_waiting_for_deletion =
+      [](const std::unique_ptr<Animation>& animation) {
+        return animation->run_state() == Animation::WAITING_FOR_DELETION &&
+               !animation->affects_pending_elements();
+      };
+  animations.erase(
+      std::remove_if(animations.begin(), animations.end(),
+                     affects_active_only_and_is_waiting_for_deletion),
+      animations.end());
+
+  if (element_animations_)
+    element_animations_->SetNeedsUpdateImplClientState(
+        removed_transform_animation, removed_opacity_animation,
+        removed_filter_animation);
+}
+
+void AnimationPlayer::PushPropertiesToImplThread(
+    AnimationPlayer* animation_player_impl) {
+  for (size_t i = 0; i < animations_.size(); ++i) {
+    Animation* current_impl =
+        animation_player_impl->GetAnimationById(animations_[i]->id());
+    if (current_impl)
+      animations_[i]->PushPropertiesTo(current_impl);
+  }
+}
+
 }  // namespace cc