Aura on Linux: Make a DesktopScreenX11 to match the windows one.

chrome/browser/chrome_browser_main_extra_parts_aura.cc

Index: chrome/browser/chrome_browser_main_extra_parts_aura.cc
diff --git a/chrome/browser/chrome_browser_main_extra_parts_aura.cc b/chrome/browser/chrome_browser_main_extra_parts_aura.cc
index a61f738e59ac837b0c56cf9e41e4ff7928cbee3f..ff3cdb188a47af52021f4d166a86179dbf0ae7c0 100644
--- a/chrome/browser/chrome_browser_main_extra_parts_aura.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_aura.cc
@@ -7,9 +7,11 @@
 #include "ui/aura/env.h"
 
 #if !defined(USE_ASH)
+#include "ui/aura/desktop/desktop_screen.h"
 #include "ui/aura/desktop/desktop_stacking_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/single_monitor_manager.h"
+#include "ui/gfx/screen.h"
 #include "ui/views/widget/native_widget_aura.h"
 #endif  // !USE_ASH
 
@@ -19,6 +21,7 @@ ChromeBrowserMainExtraPartsAura::ChromeBrowserMainExtraPartsAura()
 
 void ChromeBrowserMainExtraPartsAura::PreProfileInit() {
 #if !defined(USE_ASH)
+  gfx::Screen::SetInstance(aura::CreateDesktopScreen());
   aura::Env::GetInstance()->SetMonitorManager(new aura::SingleMonitorManager);
   stacking_client_.reset(new aura::DesktopStackingClient);
 #endif  // !USE_ASH