Makes WindowTree take the AccessPolicy

components/mus/ws/window_manager_access_policy.cc

Index: components/mus/ws/window_manager_access_policy.cc
diff --git a/components/mus/ws/window_manager_access_policy.cc b/components/mus/ws/window_manager_access_policy.cc
index 16a215b4036158028005271ca847c204590b4e92..8a4a820c25b99269408c621828b0f129294b1221 100644
--- a/components/mus/ws/window_manager_access_policy.cc
+++ b/components/mus/ws/window_manager_access_policy.cc
@@ -10,16 +10,16 @@
 namespace mus {
 namespace ws {
 
-// TODO(sky): document why this differs from default for each case. Maybe want
-// to subclass DefaultAccessPolicy.
-
-WindowManagerAccessPolicy::WindowManagerAccessPolicy(
-    ConnectionSpecificId connection_id,
-    AccessPolicyDelegate* delegate)
-    : connection_id_(connection_id), delegate_(delegate) {}
+WindowManagerAccessPolicy::WindowManagerAccessPolicy() {}
 
 WindowManagerAccessPolicy::~WindowManagerAccessPolicy() {}
 
+void WindowManagerAccessPolicy::Init(ConnectionSpecificId connection_id,
+                                     AccessPolicyDelegate* delegate) {
+  connection_id_ = connection_id;
+  delegate_ = delegate;
+}
+
 bool WindowManagerAccessPolicy::CanRemoveWindowFromParent(
     const ServerWindow* window) const {
   return true;