CC Animations: Port Impl-only-scrolling to use compositor animation timelines.

cc/animation/animation_player.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/animation/animation_player.h"
 
 #include "cc/animation/animation_host.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/animation_timeline.h"
 #include "cc/layers/layer.h"
@@ skipping 19 matching lines @@
 
   void OnTransformAnimated(const gfx::Transform& transform) override {
     player_->SetTransformMutated(is_active_, transform);
   }
 
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override {
     player_->SetScrollOffsetMutated(is_active_, scroll_offset);
   }
 
   void OnAnimationWaitingForDeletion() override {
-    // TODO(loyso): implement it.
+    // TODO(loyso): See Layer::OnAnimationWaitingForDeletion. But we always do
+    // PushProperties for AnimationTimelines for now.
   }
 
   bool IsActive() const override { return is_active_; }
 
  private:
   AnimationPlayer* player_;
   bool is_active_;
 
   DISALLOW_COPY_AND_ASSIGN(ValueObserver);
 };
@@ skipping 112 matching lines @@
   }
 }
 
 void AnimationPlayer::LayerUnregistered(int layer_id, bool is_active_tree) {
   DCHECK_EQ(layer_id_, layer_id);
   is_active_tree ? DestroyActiveValueObserver() : DestroyPendingValueObserver();
 }
 
 void AnimationPlayer::AddAnimation(scoped_ptr<Animation> animation) {
   DCHECK(layer_animation_controller_);
+  DCHECK(animation->target_property() != Animation::SCROLL_OFFSET ||
+         !animation_host_ || animation_host_->GetSupportsScrollAnimations());
   layer_animation_controller_->AddAnimation(animation.Pass());
   SetNeedsCommit();
 }
 
 void AnimationPlayer::PauseAnimation(int animation_id, double time_offset) {
   DCHECK(layer_animation_controller_);
   layer_animation_controller_->PauseAnimation(
       animation_id, base::TimeDelta::FromSecondsD(time_offset));
   SetNeedsCommit();
 }
@@ skipping 98 matching lines @@
 }
 
 void AnimationPlayer::DestroyPendingValueObserver() {
   if (layer_animation_controller_ && pending_value_observer_)
     layer_animation_controller_->RemoveValueObserver(
         pending_value_observer_.get());
   pending_value_observer_ = nullptr;
 }
 
 gfx::ScrollOffset AnimationPlayer::ScrollOffsetForAnimation() const {
-  // TODO(loyso): implement it.
+  DCHECK(layer_id_);
+  if (animation_host()) {
+    DCHECK(animation_host()->layer_tree_mutators_client());
+    return animation_host()
+        ->layer_tree_mutators_client()
+        ->GetScrollOffsetForAnimation(layer_id_);
+  }
+
   return gfx::ScrollOffset();
 }
 
 }  // namespace cc