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

chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc

Index: chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc
diff --git a/chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc b/chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc
index 7f05865a54c54ac9c29cf84fbb3b09c5516566ec..b5e6a0c971a7eead9b9e935057a9d70e6784dfb2 100644
--- a/chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc
+++ b/chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc
@@ -7,17 +7,31 @@
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/toolkit_extra_parts.h"
 #include "chrome/browser/ui/ash/ash_init.h"
+#include "chrome/browser/ui/ash/ash_util.h"
 #include "ui/aura/desktop/desktop_screen.h"
 #include "ui/aura/desktop/desktop_stacking_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/single_display_manager.h"
 #include "ui/gfx/screen.h"
+#include "ui/gfx/screen_type_delegate.h"
 
 #if defined(FILE_MANAGER_EXTENSION)
 #include "chrome/browser/ui/views/select_file_dialog_extension.h"
 #include "chrome/browser/ui/views/select_file_dialog_extension_factory.h"
 #endif
 
+#if defined(OS_WIN)
+class ScreenTypeDelegateWin : public gfx::ScreenTypeDelegate {
+ public:
+  gfx::ScreenType GetScreenTypeForNativeView(gfx::NativeView view) {
+    return chrome::IsNativeViewInAsh(view) ?
+        gfx::SCREEN_TYPE_ALTERNATE :
+        gfx::SCREEN_TYPE_NATIVE;
+  }
+ private:
+};
+#endif
+
 ChromeBrowserMainExtraPartsAsh::ChromeBrowserMainExtraPartsAsh() {
 }
 
@@ -30,7 +44,11 @@ void ChromeBrowserMainExtraPartsAsh::PreProfileInit() {
   } else {
     aura::Env::GetInstance()->SetDisplayManager(new aura::SingleDisplayManager);
     stacking_client_.reset(new aura::DesktopStackingClient);
-    gfx::Screen::SetInstance(aura::CreateDesktopScreen());
+    gfx::Screen::SetInstance(
+        gfx::SCREEN_TYPE_NATIVE, aura::CreateDesktopScreen());
+#if defined(OS_WIN)
+    gfx::Screen::SetScreenTypeDelegate(new ScreenTypeDelegateWin);
+#endif
   }
 
 #if defined(FILE_MANAGER_EXTENSION)