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

ash/wm/system_gesture_event_filter_unittest.cc

Index: ash/wm/system_gesture_event_filter_unittest.cc
diff --git a/ash/wm/system_gesture_event_filter_unittest.cc b/ash/wm/system_gesture_event_filter_unittest.cc
index 86893c997aa9ef0a044c572f4708391591a9ea40..7c795b20eaa28150db38c200e8896d28eaf70400 100644
--- a/ash/wm/system_gesture_event_filter_unittest.cc
+++ b/ash/wm/system_gesture_event_filter_unittest.cc
@@ -272,7 +272,7 @@ void MoveToDeviceControlBezelStartPosition(
 TEST_F(SystemGestureEventFilterTest, DeviceControl) {
   aura::RootWindow* root_window = Shell::GetPrimaryRootWindow();
 
-  gfx::Rect screen = gfx::Screen::GetPrimaryDisplay().bounds();
+  gfx::Rect screen = Shell::GetScreen()->GetPrimaryDisplay().bounds();
   int ypos_half = screen.height() / 2;
 
   ash::AcceleratorController* accelerator =
@@ -376,7 +376,7 @@ TEST_F(SystemGestureEventFilterTest, DeviceControl) {
 TEST_F(SystemGestureEventFilterTest, ApplicationControl) {
   aura::RootWindow* root_window = Shell::GetPrimaryRootWindow();
 
-  gfx::Rect screen = gfx::Screen::GetPrimaryDisplay().bounds();
+  gfx::Rect screen = Shell::GetScreen()->GetPrimaryDisplay().bounds();
   int ypos_half = screen.height() / 2;
 
   aura::test::TestWindowDelegate delegate;