MD Settings: Add display layout

chrome/browser/extensions/display_info_provider_chromeos.cc

 // Copyright 2014 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 "chrome/browser/extensions/display_info_provider_chromeos.h"
 
 #include <stdint.h>
 
 #include "ash/display/display_configuration_controller.h"
 #include "ash/display/display_manager.h"
@@ skipping 537 matching lines @@
     all_displays.push_back(std::move(unit));
   }
   return all_displays;
 }
 
 DisplayInfoProvider::DisplayLayoutList
 DisplayInfoProviderChromeOS::GetDisplayLayout() {
   ash::DisplayManager* display_manager =
       ash::Shell::GetInstance()->display_manager();
 
+  if (display_manager->num_connected_displays() < 2)
+    return DisplayInfoProvider::DisplayLayoutList();
+
   display::Screen* screen = display::Screen::GetScreen();
   std::vector<display::Display> displays = screen->GetAllDisplays();
 
   DisplayLayoutList result;
   for (const display::Display& display : displays) {
     const display::DisplayPlacement placement =
         display_manager->GetCurrentDisplayLayout().FindPlacementById(
             display.id());
     if (placement.display_id == display::Display::kInvalidDisplayID)
       continue;
@@ skipping 62 matching lines @@
     return nullptr;
   return iter->second.get();
 }
 
 // static
 DisplayInfoProvider* DisplayInfoProvider::Create() {
   return new DisplayInfoProviderChromeOS();
 }
 
 }  // namespace extensions