Makes WindowTree take the AccessPolicy

components/mus/ws/default_access_policy.cc

Index: components/mus/ws/default_access_policy.cc
diff --git a/components/mus/ws/default_access_policy.cc b/components/mus/ws/default_access_policy.cc
index 77e3e8b1a7b22f354c232f4105648944e2ba5d6c..e1f9ab2fdbd5441773102893a075b5c8956069e8 100644
--- a/components/mus/ws/default_access_policy.cc
+++ b/components/mus/ws/default_access_policy.cc
@@ -10,12 +10,16 @@
 namespace mus {
 namespace ws {
 
-DefaultAccessPolicy::DefaultAccessPolicy(ConnectionSpecificId connection_id,
-                                         AccessPolicyDelegate* delegate)
-    : connection_id_(connection_id), delegate_(delegate) {}
+DefaultAccessPolicy::DefaultAccessPolicy() {}
 
 DefaultAccessPolicy::~DefaultAccessPolicy() {}
 
+void DefaultAccessPolicy::Init(ConnectionSpecificId connection_id,
+                               AccessPolicyDelegate* delegate) {
+  connection_id_ = connection_id;
+  delegate_ = delegate;
+}
+
 bool DefaultAccessPolicy::CanRemoveWindowFromParent(
     const ServerWindow* window) const {
   if (!WasCreatedByThisConnection(window))