Use platform's device scale factor for cursor

ash/display/mouse_cursor_event_filter_unittest.cc

Index: ash/display/mouse_cursor_event_filter_unittest.cc
diff --git a/ash/display/mouse_cursor_event_filter_unittest.cc b/ash/display/mouse_cursor_event_filter_unittest.cc
index 1b344563208877aac7877a39a0ad8aed41953320..3325d37a0cb33edc814ee5b81f8b14be5cb32218 100644
--- a/ash/display/mouse_cursor_event_filter_unittest.cc
+++ b/ash/display/mouse_cursor_event_filter_unittest.cc
@@ -368,11 +368,11 @@ TEST_F(MouseCursorEventFilterTest, CursorDeviceScaleFactor) {
   test::CursorManagerTestApi cursor_test_api(
       Shell::GetInstance()->cursor_manager());
 
-  EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
   WarpMouseCursorIfNecessary(root_windows[0], gfx::Point(399, 200));
-  EXPECT_EQ(2.0f, cursor_test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(2.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
   WarpMouseCursorIfNecessary(root_windows[1], gfx::Point(400, 200));
-  EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
 }
 
 }  // namespace ash