Add second copy request after screen rotation to flatten the layers in animation.

ash/rotator/test/screen_rotation_animator_test_api.cc

Index: ash/rotator/test/screen_rotation_animator_test_api.cc
diff --git a/ash/rotator/test/screen_rotation_animator_test_api.cc b/ash/rotator/test/screen_rotation_animator_test_api.cc
index 0c26e474efb6c8aefc78548e1b730d7a91a62036..4c3c502bcb6df6860a8886949863c947eab2ffb6 100644
--- a/ash/rotator/test/screen_rotation_animator_test_api.cc
+++ b/ash/rotator/test/screen_rotation_animator_test_api.cc
@@ -21,6 +21,10 @@ void ScreenRotationAnimatorTestApi::DisableAnimationTimers() {
   animator_->set_disable_animation_timers_for_test(true);
 }
 
+void ScreenRotationAnimatorTestApi::EnableSmoothRotation() {
+  animator_->set_switch_smooth_rotation_for_test(true);
+}
+
 std::vector<ui::LayerAnimator*>
 ScreenRotationAnimatorTestApi::GetLayerAnimators() {
   std::vector<ui::LayerAnimator*> animators;
@@ -28,6 +32,10 @@ ScreenRotationAnimatorTestApi::GetLayerAnimators() {
     animators.insert(animators.end(),
                      animator_->old_layer_tree_owner_->root()->GetAnimator());
   }
+  if (animator_->new_layer_tree_owner_) {
+    animators.insert(animators.end(),
+                     animator_->new_layer_tree_owner_->root()->GetAnimator());
+  }
   return animators;
 }