cros: Shelf should hide after launcher animation.

The shelf bg used to shift opacity as the launcher animation began,
instead it should wait until the launcher is at shelf height.

This changes two things:
 - Notify observers of target visibility changing when the animation begins.
 - Notify observers of actual visibility changing when the animation ends.

Change-Id: I6e020406bb6fc0daf3430cec38c0abb6fb230a97
Reviewed-on: https://chromium-review.googlesource.com/c/1370368Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622041}

ash/app_list/presenter/app_list_presenter_impl.cc

@@ -101,7 +101,6 @@ AppListPresenterImpl::AppListPresenterImpl(
 
 AppListPresenterImpl::~AppListPresenterImpl() {
   Dismiss(base::TimeTicks());
-  delegate_.reset();
   // Ensures app list view goes before the controller since pagination model
   // lives in the controller and app list view would access it on destruction.
   if (view_) {
@@ -169,7 +168,6 @@ void AppListPresenterImpl::Dismiss(base::TimeTicks event_time_stamp) {
   delegate_->OnClosing();
   ScheduleAnimation();
   NotifyTargetVisibilityChanged(GetTargetVisibility());
-  NotifyVisibilityChanged(GetTargetVisibility(), display_id);
   base::RecordAction(base::UserMetricsAction("Launcher_Dismiss"));
 }
 
@@ -390,6 +388,8 @@ void AppListPresenterImpl::OnWindowFocused(aura::Window* gained_focus,
 // AppListPresenterImpl, ui::ImplicitAnimationObserver implementation:
 
 void AppListPresenterImpl::OnImplicitAnimationsCompleted() {
+  NotifyVisibilityChanged(GetTargetVisibility(), GetDisplayId());
+
   if (is_visible_) {
     view_->GetWidget()->Activate();
   } else {

chrome/browser/ui/app_list/app_list_client_interactive_uitest.cc

@@ -22,5 +22,5 @@ IN_PROC_BROWSER_TEST_F(AppListClientInteractiveTest, ShowAndDismiss) {
   ASSERT_TRUE(client->app_list_visible());
   client->DismissView();
   client->FlushMojoForTesting();
-  ASSERT_FALSE(client->app_list_visible());
+  ASSERT_FALSE(client->app_list_target_visibility());
 }