TestScreen shouldn't be marked aura export

ash/wm/base_layout_manager_unittest.cc

Index: ash/wm/base_layout_manager_unittest.cc
diff --git a/ash/wm/base_layout_manager_unittest.cc b/ash/wm/base_layout_manager_unittest.cc
index b6e49011ddaa764284a29a1bba942dd6cc74821e..f8045a493e4bb6ff8c6db765903e9fed46913253 100644
--- a/ash/wm/base_layout_manager_unittest.cc
+++ b/ash/wm/base_layout_manager_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/base_layout_manager.h"
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
@@ -11,7 +12,6 @@
 #include "base/compiler_specific.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/test/test_windows.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/aura/window.h"
@@ -27,7 +27,7 @@ class BaseLayoutManagerTest : public test::AshTestBase {
 
   virtual void SetUp() OVERRIDE {
     test::AshTestBase::SetUp();
-    Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+    Shell::GetInstance()->SetScreenWorkAreaInsets(
         gfx::Insets(1, 2, 3, 4));
     Shell::GetRootWindow()->SetHostSize(gfx::Size(800, 600));
     aura::Window* default_container = Shell::GetInstance()->GetContainer(