Fix close animation target y issue

This is a follow up fix for go/cgcl/1272238.

Bug: 893521
Change-Id: I3ea08e13eb0909e7b216448d9cdad2761c5e4647
Reviewed-on: https://chromium-review.googlesource.com/c/1277385Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598873}

ash/app_list/views/app_list_view.cc

@@ -1300,6 +1300,10 @@ void AppListView::StartAnimationForState(AppListViewState target_state) {
   if (is_side_shelf_)
     return;
 
+  // The close animation is handled by the delegate.
+  if (target_state == AppListViewState::CLOSED)
+    return;
+
   const display::Display display = GetDisplayNearestView();
   const int target_state_y = GetPreferredWidgetYForState(target_state);
   gfx::Rect target_bounds = fullscreen_widget_->GetNativeView()->bounds();