Transfer LayerImpl ownership to LayerTreeImpl

cc/layers/layer_impl_unittest.cc

Index: cc/layers/layer_impl_unittest.cc
diff --git a/cc/layers/layer_impl_unittest.cc b/cc/layers/layer_impl_unittest.cc
index e88d007d2f842ea1c961d158c75a0d37ba60c170..7e8c3275280441854f97d7493f406ef53980c937 100644
--- a/cc/layers/layer_impl_unittest.cc
+++ b/cc/layers/layer_impl_unittest.cc
@@ -153,9 +153,9 @@ TEST(LayerImplTest, VerifyLayerChangesAreTrackedProperly) {
       PropertyTrees::ResetFlags::ALL_TREES);
 
   root->AddChild(LayerImpl::Create(host_impl.active_tree(), 7));
-  LayerImpl* child = root->children()[0].get();
+  LayerImpl* child = root->children()[0];
   child->AddChild(LayerImpl::Create(host_impl.active_tree(), 8));
-  LayerImpl* grand_child = child->children()[0].get();
+  LayerImpl* grand_child = child->children()[0];
   root->SetScrollClipLayer(root_clip->id());
   host_impl.active_tree()->BuildPropertyTreesForTesting();
 
@@ -516,7 +516,7 @@ class LayerImplScrollTest : public testing::Test {
   }
 
   LayerImpl* layer() {
-    return host_impl_.active_tree()->root_layer()->children()[0].get();
+    return host_impl_.active_tree()->root_layer()->children()[0];
   }
 
   ScrollTree* scroll_tree(LayerImpl* layer_impl) {