Fix for out-of-sync scale factor issue

ash/display/multi_display_manager.cc

Index: ash/display/multi_display_manager.cc
diff --git a/ash/display/multi_display_manager.cc b/ash/display/multi_display_manager.cc
index 6df0887384e8c1b25d1adf9722440237cbef4638..0a4410392b3ab56246e81a5b04617da335c63c1f 100644
--- a/ash/display/multi_display_manager.cc
+++ b/ash/display/multi_display_manager.cc
@@ -317,7 +317,9 @@ const gfx::Display& MultiDisplayManager::GetDisplayNearestWindow(
     return DisplayController::GetPrimaryDisplay();
   const RootWindow* root = window->GetRootWindow();
   MultiDisplayManager* manager = const_cast<MultiDisplayManager*>(this);
-  return root ? manager->FindDisplayForRootWindow(root) : GetInvalidDisplay();
+  return root ?
+      manager->FindDisplayForRootWindow(root) :
+      *manager->GetDisplayAt(0);
 }
 
 const gfx::Display& MultiDisplayManager::GetDisplayNearestPoint(