cc: Clean up root_layer code in LTI

cc/layers/layer_list_iterator_unittest.cc

Index: cc/layers/layer_list_iterator_unittest.cc
diff --git a/cc/layers/layer_list_iterator_unittest.cc b/cc/layers/layer_list_iterator_unittest.cc
index 6900ae3913db869c958d7d73318c5d5d2e4cd474..cb538e08817f181605ab3c034045c44be85dd940 100644
--- a/cc/layers/layer_list_iterator_unittest.cc
+++ b/cc/layers/layer_list_iterator_unittest.cc
@@ -239,7 +239,7 @@ TEST(LayerListIteratorTest, VerifyTraversalOrderImpl) {
   layer1->test_properties()->AddChild(std::move(layer2));
   layer1->test_properties()->AddChild(std::move(layer5));
 
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;
@@ -263,7 +263,7 @@ TEST(LayerListIteratorTest, VerifySingleLayerImpl) {
   // This test constructs a tree consisting of a single layer.
   std::unique_ptr<LayerImpl> layer1 =
       LayerImpl::Create(host_impl.active_tree(), 1);
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;
@@ -329,7 +329,7 @@ TEST(LayerListReverseIteratorTest, VerifyTraversalOrderImpl) {
   layer1->test_properties()->AddChild(std::move(layer2));
   layer1->test_properties()->AddChild(std::move(layer5));
 
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 7;
@@ -355,7 +355,7 @@ TEST(LayerListReverseIteratorTest, VerifySingleLayerImpl) {
   // This test constructs a tree consisting of a single layer.
   std::unique_ptr<LayerImpl> layer1 =
       LayerImpl::Create(host_impl.active_tree(), 1);
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;