Support creation of toplevel mus::Windows on separate displays

ash/mus/bridge/wm_root_window_controller_mus.cc

Index: ash/mus/bridge/wm_root_window_controller_mus.cc
diff --git a/ash/mus/bridge/wm_root_window_controller_mus.cc b/ash/mus/bridge/wm_root_window_controller_mus.cc
index ff89cb61f33b7aec51a3600131d41abf2f71041d..1e450c928176bf1085aec51ec4ed00ef15e992fb 100644
--- a/ash/mus/bridge/wm_root_window_controller_mus.cc
+++ b/ash/mus/bridge/wm_root_window_controller_mus.cc
@@ -49,10 +49,26 @@ const WmRootWindowControllerMus* WmRootWindowControllerMus::Get(
     const ui::Window* window) {
   if (!window)
     return nullptr;
-
   return window->GetRoot()->GetLocalProperty(kWmRootWindowControllerKey);
 }
 
+gfx::Rect* WmRootWindowControllerMus::ConvertWindowToScreen(
+    const WmWindowMus* source,
+    const ui::Window* window) const {
+  gfx::Point screen_point_top_right =
+      ConvertPointToScreen(source, window->bounds().top_right());
+
+  gfx::Point screen_point_bottom_left =
+      ConvertPointToScreen(source, window->bounds().bottom_left());
+
+  gfx::Rect* screen_bound =
+      new gfx::Rect(screen_point_bottom_left.x(), screen_point_top_right.y(),
+                    screen_point_top_right.x() - screen_point_bottom_left.x(),
+                    screen_point_bottom_left.y() - screen_point_top_right.y());
+
+  return screen_bound;
+}
+
 gfx::Point WmRootWindowControllerMus::ConvertPointToScreen(
     const WmWindowMus* source,
     const gfx::Point& point) const {