Add context to gfx::Screen calls in support of simultaneous desktop+ash

chrome/browser/ui/window_sizer/window_sizer_gtk.cc

Index: chrome/browser/ui/window_sizer/window_sizer_gtk.cc
diff --git a/chrome/browser/ui/window_sizer/window_sizer_gtk.cc b/chrome/browser/ui/window_sizer/window_sizer_gtk.cc
index 526f0ea863680bb1b228852cd6d87e7ae503eae6..88e81a21d14851a2337d5a94a9f3eea88ccd8e60 100644
--- a/chrome/browser/ui/window_sizer/window_sizer_gtk.cc
+++ b/chrome/browser/ui/window_sizer/window_sizer_gtk.cc
@@ -22,7 +22,8 @@ const int WindowSizer::kWindowTilePixels = 10;
 // static
 gfx::Point WindowSizer::GetDefaultPopupOrigin(const gfx::Size& size,
                                               chrome::HostDesktopType type) {
-  gfx::Rect monitor_bounds = gfx::Screen::GetPrimaryDisplay().work_area();
+  gfx::Rect monitor_bounds = gfx::Screen::GetNativeScreen()->
+      GetPrimaryDisplay().work_area();
   gfx::Point corner(monitor_bounds.x(), monitor_bounds.y());
 
   if (Browser* browser = browser::FindLastActiveWithHostDesktopType(type)) {