Return primary display in gfx::Screen during the shutdown

ash/screen_ash.cc

Index: ash/screen_ash.cc
diff --git a/ash/screen_ash.cc b/ash/screen_ash.cc
index b0ade929805040de8a2fec943be5a17687c1097c..bbda5ad8a7c3f3c8a173d38dbb03f6cea91a3042 100644
--- a/ash/screen_ash.cc
+++ b/ash/screen_ash.cc
@@ -130,18 +130,26 @@ int ScreenAsh::GetNumDisplays() const {
 }
 
 std::vector<gfx::Display> ScreenAsh::GetAllDisplays() const {
+  if (!Shell::HasInstance())
+    return std::vector<gfx::Display>(1, GetPrimaryDisplay());
   return GetDisplayManager()->displays();
 }
 
 gfx::Display ScreenAsh::GetDisplayNearestWindow(gfx::NativeView window) const {
+  if (!Shell::HasInstance())
+    return GetPrimaryDisplay();
   return GetDisplayController()->GetDisplayNearestWindow(window);
 }
 
 gfx::Display ScreenAsh::GetDisplayNearestPoint(const gfx::Point& point) const {
+  if (!Shell::HasInstance())
+    return GetPrimaryDisplay();
   return GetDisplayController()->GetDisplayNearestPoint(point);
 }
 
 gfx::Display ScreenAsh::GetDisplayMatching(const gfx::Rect& match_rect) const {
+  if (!Shell::HasInstance())
+    return GetPrimaryDisplay();
   return GetDisplayController()->GetDisplayMatching(match_rect);
 }