Support creation of toplevel mus::Windows on separate displays

ash/mus/window_manager_unittest.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 <memory>
 
+#include "ash/mus/test/wm_test_base.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "services/service_manager/public/cpp/service_test.h"
 #include "services/ui/public/cpp/window.h"
 #include "services/ui/public/cpp/window_tree_client.h"
 #include "services/ui/public/cpp/window_tree_client_delegate.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
 
 namespace ash {
 namespace mus {
@@ skipping 56 matching lines @@
   // |child_window|. This blocks until it succeeds.
   ui::mojom::WindowTreeClientPtr tree_client;
   auto tree_client_request = GetProxy(&tree_client);
   child_window->Embed(std::move(tree_client), base::Bind(&OnEmbed));
   std::unique_ptr<ui::WindowTreeClient> child_client(new ui::WindowTreeClient(
       &window_tree_delegate, nullptr, std::move(tree_client_request)));
   child_client->WaitForEmbed();
   ASSERT_TRUE(!child_client->GetRoots().empty());
 }
 
+using WindowManagerAshTest = mus::WmTestBase;
+
+TEST_F(WindowManagerAshTest, isWidgetShownInCorrectDisplay) {
+  if (!SupportsMultipleDisplays())
+    return;
+
+  UpdateDisplay("400x400,400x400");
+  EXPECT_NE(GetPrimaryRootWindowController(),
+            GetSecondaryRootWindowController());
+
+  ui::Window* ui_primary_window =
+      CreateFullscreenTestWindow(GetPrimaryRootWindowController());
+  ui::Window* ui_secondary_window =
+      CreateFullscreenTestWindow(GetSecondaryRootWindowController());
+
+  DCHECK(ui_primary_window);
+  DCHECK(ui_secondary_window);
+
+  EXPECT_NE(ui_primary_window->display_id(), ui_secondary_window->display_id());
+}
+
 }  // namespace mus
 }  // namespace ash