Fade out overlay scrollbar after page load

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 3e6e1d517960012b4964f9fb3fd7bb31d5ebe032..329ad1c12d7d3cff00b27e8ca8411f1d08151628 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -2919,7 +2919,6 @@ class LayerTreeHostImplTestScrollbarAnimation : public LayerTreeHostImplTest {
     LayerImpl* root = host_impl_->active_tree()->InnerViewportContainerLayer();
     scrollbar->SetScrollElementId(scroll->element_id());
     root->test_properties()->AddChild(std::move(scrollbar));
-    scroll->set_needs_show_scrollbars(true);
     host_impl_->active_tree()->BuildPropertyTreesForTesting();
     host_impl_->active_tree()->DidBecomeActive();
     host_impl_->active_tree()->HandleScrollbarShowRequestsFromMain();
@@ -3223,7 +3222,6 @@ TEST_F(LayerTreeHostImplTest, ScrollbarVisibilityChangeCausesRedrawAndCommit) {
   scrollbar->SetPosition(gfx::PointF(90, 0));
   container->test_properties()->AddChild(std::move(scrollbar));
   host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
-  scroll->set_needs_show_scrollbars(true);
   host_impl_->pending_tree()->BuildPropertyTreesForTesting();
   host_impl_->ActivateSyncTree();