SetDeviceScaleFactorForTest

ui/aura/test/aura_test_helper.h

Index: ui/aura/test/aura_test_helper.h
diff --git a/ui/aura/test/aura_test_helper.h b/ui/aura/test/aura_test_helper.h
index 3a755e06ab4db0caf20c71fb9223fbba1cb89b18..c90850d8be07679d2232344a6feb83f3f5ac817e 100644
--- a/ui/aura/test/aura_test_helper.h
+++ b/ui/aura/test/aura_test_helper.h
@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/macros.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
 
@@ -52,9 +53,9 @@ class AuraTestHelper {
   // Flushes message loop.
   void RunAllPendingInMessageLoop();
 
-  Window* root_window() { return host_->window(); }
-  ui::EventProcessor* event_processor() { return host_->event_processor(); }
-  WindowTreeHost* host() { return host_.get(); }
+  Window* root_window() { return host()->window(); }
+  ui::EventProcessor* event_processor() { return host()->event_processor(); }
+  WindowTreeHost* host() { return test_screen_->host(); }
 
   TestScreen* test_screen() { return test_screen_.get(); }