Support creation of toplevel mus::Windows on separate displays

ash/mus/test/wm_test_base.h

Index: ash/mus/test/wm_test_base.h
diff --git a/ash/mus/test/wm_test_base.h b/ash/mus/test/wm_test_base.h
index 8c17d39f29eff12eae1f9b1ad7ff7056c9f8e89e..e11376d459ccd1284e8908589f382aff16d878e6 100644
--- a/ash/mus/test/wm_test_base.h
+++ b/ash/mus/test/wm_test_base.h
@@ -10,6 +10,7 @@
 
 #include "base/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/display/display.h"
 #include "ui/wm/public/window_types.h"
 
 namespace display {
@@ -58,7 +59,12 @@ class WmTestBase : public testing::Test {
   ui::Window* CreateTestWindow(const gfx::Rect& bounds);
   ui::Window* CreateTestWindow(const gfx::Rect& bounds,
                                ui::wm::WindowType window_type);
-  ui::Window* CreateFullscreenTestWindow();
+
+  // Creates a full screen visbiel top level window window  By default,

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

- visible
- missing period
- don't explain the default value of display_id - that's clear from the
signature. Say how it's used instead (the window should be displayed on the
display with that id).

[thanhph, 2016/11/22 23:18:02]

Done, thanks!

+  // if display_id value is not provided, kInvalidDisplayID is used to set as
+  // the display id for mus window.
+  ui::Window* CreateFullscreenTestWindow(
+      int64_t display_id = display::Display::kInvalidDisplayID);
 
   // Creates a window parented to |parent|. The returned window is visible.
   ui::Window* CreateChildTestWindow(ui::Window* parent,