Inform window manager about modal windows in mus+ash.

ui/aura/mus/window_tree_client.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 "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 1378 matching lines @@
                                                        name, &data);
     if (result) {
       delegate_->GetPropertyConverter()->SetPropertyFromTransportValue(
           window->GetWindow(), name, data.get());
     }
   }
   if (window_manager_internal_client_)
     window_manager_internal_client_->WmResponse(change_id, result);
 }
 
+void WindowTreeClient::WmSetModalType(uint32_t change_id,
+                                      Id window_id,
+                                      ui::ModalType type) {
+  WindowMus* window = GetWindowByServerId(window_id);
+  bool result = false;
+  if (window) {
+    DCHECK(window_manager_delegate_);

[sky, 2017/03/14 21:16:23]

I think you should directly set the modal type here. I can't think of a reason
to call the delegate. IF we need to add it at some point, we can do that.

[Hadi, 2017/03/17 16:16:32]

Done.

+    result =
+        window_manager_delegate_->OnWmSetModalType(window->GetWindow(), type);
+  }
+  if (window_manager_internal_client_)
+    window_manager_internal_client_->WmResponse(change_id, result);
+}
+
 void WindowTreeClient::WmSetCanFocus(Id window_id, bool can_focus) {
   WindowMus* window = GetWindowByServerId(window_id);
   if (window)
     window_manager_delegate_->OnWmSetCanFocus(window->GetWindow(), can_focus);
 }
 
 void WindowTreeClient::WmCreateTopLevelWindow(
     uint32_t change_id,
     ClientSpecificId requesting_client_id,
     const std::unordered_map<std::string, std::vector<uint8_t>>&
@@ skipping 414 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura