mus: Server-side implementation of modal windows

components/mus/ws/window_tree_impl.cc

 // Copyright 2014 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/window_tree_impl.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 210 matching lines @@
   if (window && transient_window && !transient_window->Contains(window) &&
       access_policy_->CanAddTransientWindow(window, transient_window)) {
     Operation op(this, connection_manager_,
                  OperationType::ADD_TRANSIENT_WINDOW);
     window->AddTransientWindow(transient_window);
     return true;
   }
   return false;
 }
 
+bool WindowTreeImpl::SetAsModal(const ClientWindowId& window_id) {
+  ServerWindow* window = GetWindowByClientId(window_id);
+  if (window && access_policy_->CanSetAsModal(window)) {
+    window->SetAsModal();
+    return true;
+  }
+  return false;
+}
+
 std::vector<const ServerWindow*> WindowTreeImpl::GetWindowTree(
     const ClientWindowId& window_id) const {
   const ServerWindow* window = GetWindowByClientId(window_id);
   std::vector<const ServerWindow*> windows;
   if (window)
     GetWindowTreeImpl(window, &windows);
   return windows;
 }
 
 bool WindowTreeImpl::SetWindowVisibility(const ClientWindowId& window_id,
@@ skipping 732 matching lines @@
       access_policy_->CanRemoveTransientWindowFromParent(transient_window)) {
     success = true;
     Operation op(this, connection_manager_,
                  OperationType::REMOVE_TRANSIENT_WINDOW_FROM_PARENT);
     transient_window->transient_parent()->RemoveTransientWindow(
         transient_window);
   }
   client_->OnChangeCompleted(change_id, success);
 }
 
+void WindowTreeImpl::SetAsModal(uint32_t change_id, Id window_id) {
+  client_->OnChangeCompleted(change_id, SetAsModal(ClientWindowId(window_id)));
+}
+
 void WindowTreeImpl::ReorderWindow(uint32_t change_id,
                                    Id window_id,
                                    Id relative_window_id,
                                    mojom::OrderDirection direction) {
   bool success = false;
   ServerWindow* window = GetWindowByClientId(ClientWindowId(window_id));
   ServerWindow* relative_window =
       GetWindowByClientId(ClientWindowId(relative_window_id));
   if (CanReorderWindow(window, relative_window, direction)) {
     success = true;
@@ skipping 372 matching lines @@
 
   for (const auto* root : roots_) {
     if (root->Contains(window))
       return true;
   }
   return false;
 }
 
 }  // namespace ws
 }  // namespace mus