Make WindowTree::SetModal() take the type.

services/ui/ws/modal_window_controller.cc

 // Copyright 2016 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/modal_window_controller.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "services/ui/ws/event_dispatcher.h"
 #include "services/ui/ws/server_window.h"
@@ skipping 30 matching lines @@
   for (auto it = system_modal_windows_.begin();
        it != system_modal_windows_.end(); it++) {
     (*it)->RemoveObserver(this);
   }
 }
 
 void ModalWindowController::AddSystemModalWindow(ServerWindow* window) {
   DCHECK(window);
   DCHECK(!base::ContainsValue(system_modal_windows_, window));
 
-  window->SetModal();
+  window->SetModal(true);
   system_modal_windows_.push_back(window);
   window_drawn_trackers_.insert(make_pair(
       window, base::MakeUnique<ServerWindowDrawnTracker>(window, this)));
   window->AddObserver(this);
 
   event_dispatcher_->ReleaseCaptureBlockedByModalWindow(window);
 }
 
 bool ModalWindowController::IsWindowBlockedBy(
     const ServerWindow* window,
@@ skipping 52 matching lines @@
   // Move the most recently shown window to the end of the list.
   auto it = std::find(system_modal_windows_.begin(),
                       system_modal_windows_.end(), window);
   DCHECK(it != system_modal_windows_.end());
   system_modal_windows_.splice(system_modal_windows_.end(),
                                system_modal_windows_, it);
 }
 
 }  // namespace ws
 }  // namespace ui