Make WindowTree::SetModal() take the type.

services/ui/ws/server_window.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 "services/ui/ws/server_window.h"
 
 #include <inttypes.h>
 #include <stddef.h>
 
 #include "base/memory/ptr_util.h"
@@ skipping 258 matching lines @@
   // If |child| and its former transient parent share the same parent, |child|
   // should be restacked properly so it is not among transient children of its
   // former parent, anymore.
   if (parent() == child->parent())
     RestackTransientDescendants(this, &GetStackingTarget, &ReorderImpl);
 
   for (auto& observer : observers_)
     observer.OnTransientWindowRemoved(this, child);
 }
 
-void ServerWindow::SetModal() {
-  is_modal_ = true;
+void ServerWindow::SetModal(bool is_modal) {
+  is_modal_ = is_modal;
 }
 
 bool ServerWindow::Contains(const ServerWindow* window) const {
   for (const ServerWindow* parent = window; parent; parent = parent->parent_) {
     if (parent == this)
       return true;
   }
   return false;
 }
 
@@ skipping 190 matching lines @@
   window->OnStackingChanged();
 }
 
 // static
 ServerWindow** ServerWindow::GetStackingTarget(ServerWindow* window) {
   return &window->stacking_target_;
 }
 
 }  // namespace ws
 }  // namespace ui