mus: Allow embedder to intercept events.

components/mus/ws/display_binding.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/ws/display_binding.h"
 
 #include "base/memory/ptr_util.h"
 #include "components/mus/ws/display.h"
 #include "components/mus/ws/window_manager_access_policy.h"
 #include "components/mus/ws/window_server.h"
 #include "components/mus/ws/window_tree.h"
 #include "services/shell/public/interfaces/connector.mojom.h"
 
 namespace mus {
 namespace ws {
 
 DisplayBindingImpl::DisplayBindingImpl(mojom::WindowTreeHostRequest request,
                                        Display* display,
                                        const UserId& user_id,
                                        mojom::WindowTreeClientPtr client,
                                        WindowServer* window_server)
     : window_server_(window_server),
       user_id_(user_id),
       binding_(display, std::move(request)),
       client_(std::move(client)) {}
 
 DisplayBindingImpl::~DisplayBindingImpl() {}
 
 WindowTree* DisplayBindingImpl::CreateWindowTree(ServerWindow* root) {
+  const uint32_t embed_flags = 0;
   WindowTree* tree = window_server_->EmbedAtWindow(
-      root, user_id_, std::move(client_),
+      root, user_id_, std::move(client_), embed_flags,
       base::WrapUnique(new WindowManagerAccessPolicy));
   tree->ConfigureWindowManager();
   return tree;
 }
 
 }  // namespace ws
 }  // namespace mus