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

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index db4d26304d5db2e186d6bd0a4c2ab87ec37bbad6..fb7dbffa07d8ec0e708a1b0ded4025525d14c3b3 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -3374,6 +3374,10 @@ void LayerTreeHostImpl::ScrollAnimationCreate(
     LayerImpl* layer_impl,
     const gfx::ScrollOffset& target_offset,
     const gfx::ScrollOffset& current_offset) {
+  if (animation_host_)
+    return animation_host_->ImplOnlyScrollAnimationCreate(
+        layer_impl->id(), target_offset, current_offset);
+
   scoped_ptr<ScrollOffsetAnimationCurve> curve =
       ScrollOffsetAnimationCurve::Create(target_offset,
                                          EaseInOutTimingFunction::Create());
@@ -3390,6 +3394,11 @@ void LayerTreeHostImpl::ScrollAnimationCreate(
 bool LayerTreeHostImpl::ScrollAnimationUpdateTarget(
     LayerImpl* layer_impl,
     const gfx::Vector2dF& scroll_delta) {
+  if (animation_host_)
+    return animation_host_->ImplOnlyScrollAnimationUpdateTarget(
+        layer_impl->id(), scroll_delta, layer_impl->MaxScrollOffset(),
+        CurrentBeginFrameArgs().frame_time);
+
   Animation* animation =
       layer_impl->layer_animation_controller()
           ? layer_impl->layer_animation_controller()->GetAnimation(
@@ -3524,4 +3533,19 @@ void LayerTreeHostImpl::SetLayerScrollOffsetMutated(
   }
 }
 
+void LayerTreeHostImpl::ScrollOffsetAnimationFinished() {
+  ScrollEnd();
+}
+
+gfx::ScrollOffset LayerTreeHostImpl::GetScrollOffsetForAnimation(
+    int layer_id) const {
+  if (active_tree()) {
+    LayerAnimationValueProvider* layer = active_tree()->LayerById(layer_id);
+    if (layer)
+      return layer->ScrollOffsetForAnimation();
+  }
+
+  return gfx::ScrollOffset();
+}
+
 }  // namespace cc