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

chrome/browser/ui/ash/ash_util.cc

Index: chrome/browser/ui/ash/ash_util.cc
diff --git a/chrome/browser/ui/ash/ash_util.cc b/chrome/browser/ui/ash/ash_util.cc
index 488cc4c3f8cef178575b9d5369410285ff35d061..dff6f1f6a06b02f9419c43212e97d3b10abb56e1 100644
--- a/chrome/browser/ui/ash/ash_util.cc
+++ b/chrome/browser/ui/ash/ash_util.cc
@@ -6,7 +6,9 @@
 
 #include "ash/shell.h"
 #include "chrome/browser/ui/ash/ash_init.h"
+#include "chrome/browser/ui/host_desktop.h"
 #include "ui/aura/root_window.h"
+#include "ui/gfx/screen.h"
 
 namespace chrome {
 
@@ -36,10 +38,13 @@ bool IsNativeWindowInAsh(gfx::NativeWindow native_window) {
 }
 
 void ToggleAshDesktop() {
+  ScopedForceDesktopType force_ash(HOST_DESKTOP_TYPE_ASH);
+  gfx::Screen::ForceScreenTypeOverride(gfx::SCREEN_TYPE_ALTERNATE);
   if (!ash::Shell::HasInstance())
     OpenAsh();
   else
     CloseAsh();
+  gfx::Screen::ForceScreenTypeOverride(gfx::SCREEN_TYPE_COUNT);
 }
 
 }  // namespace chrome