Flip the flag to enable smooth screen rotation by default.

ash/accelerators/accelerator_controller_unittest.cc

Index: ash/accelerators/accelerator_controller_unittest.cc
diff --git a/ash/accelerators/accelerator_controller_unittest.cc b/ash/accelerators/accelerator_controller_unittest.cc
index c17dcf10aa3dedbe8f4172d076be33ae2ff6b949..30c996472e723ecd6e3e1bc95020f905d3fc2f1f 100644
--- a/ash/accelerators/accelerator_controller_unittest.cc
+++ b/ash/accelerators/accelerator_controller_unittest.cc
@@ -18,6 +18,7 @@
 #include "ash/system/keyboard_brightness_control_delegate.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/test/ash_test_base.h"
+#include "ash/test/display_configuration_controller_test_api.h"
 #include "ash/test/lock_state_controller_test_api.h"
 #include "ash/test/test_screenshot_delegate.h"
 #include "ash/test/test_session_state_animator.h"
@@ -519,6 +520,10 @@ TEST_F(AcceleratorControllerTest, RotateScreen) {
     return;
 
   display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
+  test::DisplayConfigurationControllerTestApi controller_testapi(
+      Shell::Get()->display_configuration_controller());
+  controller_testapi.SetEnableScreenRotationAnimator(display.id(), false);
+
   display::Display::Rotation initial_rotation =
       GetActiveDisplayRotation(display.id());
   ui::test::EventGenerator& generator = GetEventGenerator();
@@ -530,6 +535,7 @@ TEST_F(AcceleratorControllerTest, RotateScreen) {
       GetActiveDisplayRotation(display.id());
   // |new_rotation| is determined by the AcceleratorControllerDelegate.
   EXPECT_NE(initial_rotation, new_rotation);
+  controller_testapi.SetEnableScreenRotationAnimator(display.id(), true);
 }
 
 TEST_F(AcceleratorControllerTest, AutoRepeat) {