cc: Start using raster/eviction iterators.

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 948c2bae3204342669eec1748c24ff0e0bdabd5f..9a3272929df9d71912864ceba60d2e0c7162f0ec 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -1457,6 +1457,10 @@ void LayerTreeImpl::InputScrollAnimationFinished() {
   layer_tree_host_impl_->ScrollEnd();
 }
 
+bool LayerTreeImpl::SmoothnessTakesPriority() const {
+  return layer_tree_host_impl_->GetTreePriority() == SMOOTHNESS_TAKES_PRIORITY;
+}
+
 BlockingTaskRunner* LayerTreeImpl::BlockingMainThreadTaskRunner() const {
   return proxy()->blocking_main_thread_task_runner();
 }