Convert //cc from scoped_ptr to std::unique_ptr.

cc/layers/layer_position_constraint_unittest.cc

Index: cc/layers/layer_position_constraint_unittest.cc
diff --git a/cc/layers/layer_position_constraint_unittest.cc b/cc/layers/layer_position_constraint_unittest.cc
index d64cf4f44da0da05b590172e778cffb50f3d5202..9c060eab43a99ccfceb9131965b9e74cd60ab6a1 100644
--- a/cc/layers/layer_position_constraint_unittest.cc
+++ b/cc/layers/layer_position_constraint_unittest.cc
@@ -75,7 +75,7 @@ class LayerPositionConstraintTest : public testing::Test {
         great_grand_child_impl_(nullptr) {
     layer_tree_host_->InitializeForTesting(
         TaskRunnerProvider::Create(nullptr, nullptr),
-        scoped_ptr<Proxy>(new FakeProxy), nullptr);
+        std::unique_ptr<Proxy>(new FakeProxy), nullptr);
     CreateTreeForTest();
     fixed_to_top_left_.set_is_fixed_position(true);
     fixed_to_bottom_right_.set_is_fixed_position(true);
@@ -168,7 +168,7 @@ class LayerPositionConstraintTest : public testing::Test {
  protected:
   FakeLayerTreeHostClient fake_client_;
   TestTaskGraphRunner task_graph_runner_;
-  scoped_ptr<FakeLayerTreeHost> layer_tree_host_;
+  std::unique_ptr<FakeLayerTreeHost> layer_tree_host_;
   scoped_refptr<Layer> root_;
   scoped_refptr<Layer> inner_viewport_container_layer_;
   scoped_refptr<Layer> scroll_layer_;