Support creation of toplevel mus::Windows on separate displays

ash/mus/test/wm_test_base.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 "ash/mus/test/wm_test_base.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/mus/bridge/wm_window_mus_test_api.h"
@@ skipping 105 matching lines @@
 
   ui::Window* window = test_helper_->GetRootsOrderedByDisplayId()[0]
                            ->window_manager()
                            ->NewTopLevelWindow(&properties);
   window->SetVisible(true);
   // Most tests expect a minimum size of 0x0.
   WmWindowMusTestApi(WmWindowMus::Get(window)).set_use_empty_minimum_size(true);
   return window;
 }
 
-ui::Window* WmTestBase::CreateFullscreenTestWindow() {
+ui::Window* WmTestBase::CreateFullscreenTestWindow(int64_t display_id = 0) {
   std::map<std::string, std::vector<uint8_t>> properties;
   properties[ui::mojom::WindowManager::kShowState_Property] =
       mojo::ConvertTo<std::vector<uint8_t>>(
           static_cast<int32_t>(ui::mojom::ShowState::FULLSCREEN));
+
+  if (display_id)

[mfomitchev, 2016/11/18 21:23:40]

Need braces around multiline statement.

[thanhph, 2016/11/21 14:37:53]

Done.

+    properties[ui::mojom::WindowManager::kInitialDisplayId_Property] =
+        mojo::ConvertTo<std::vector<uint8_t>>(display_id);

[mfomitchev, 2016/11/18 21:23:40]

Is 0 display id guaranteed to be the same as having no display id? Because as is
if I call CreateFullscreenTestWindow(0), it won't set kInitialDisplayId_Property
prop.

[thanhph, 2016/11/21 14:37:53]

Done. I change from 0 to display::Display::kInvalidDisplayID instead.

[mfomitchev, 2016/11/22 22:53:16]

Wait, this is different. Now we can't call this method w/o giving it a display
id - it won't work.

+
   ui::Window* window = test_helper_->GetRootsOrderedByDisplayId()[0]
                            ->window_manager()
                            ->NewTopLevelWindow(&properties);
   window->SetVisible(true);
   return window;
 }
 
 ui::Window* WmTestBase::CreateChildTestWindow(ui::Window* parent,
                                               const gfx::Rect& bounds) {
   std::map<std::string, std::vector<uint8_t>> properties;
@@ skipping 16 matching lines @@
   test_helper_->Init();
 }
 
 void WmTestBase::TearDown() {
   teardown_called_ = true;
   test_helper_.reset();
 }
 
 }  // namespace mus
 }  // namespace ash