Fix homecher launching app behavior

Changes:
In homecher, folder or search result page is closed when an app is
launched or a search result is opened.

Bug: 853846
Change-Id: I92edf732b01bb9c5b0f97ff2206bd09b2b6130ca
Reviewed-on: https://chromium-review.googlesource.com/1175417
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583282}

ash/app_list/app_list_controller_impl.cc

@@ -568,6 +568,9 @@ void AppListControllerImpl::OpenSearchResult(const std::string& result_id,
 
   if (client_)
     client_->OpenSearchResult(result_id, event_flags);
+
+  if (IsHomeLauncherEnabledInTabletMode() && presenter_.IsVisible())
+    presenter_.GetView()->ResetToInitialState();
 }
 
 void AppListControllerImpl::InvokeSearchResultAction(
@@ -614,6 +617,9 @@ void AppListControllerImpl::ActivateItem(const std::string& id,
                                          int event_flags) {
   if (client_)
     client_->ActivateItem(id, event_flags);
+
+  if (IsHomeLauncherEnabledInTabletMode() && presenter_.IsVisible())
+    presenter_.GetView()->ResetToInitialState();
 }
 
 void AppListControllerImpl::GetContextMenuModel(

ash/app_list/views/app_list_view.cc

@@ -395,6 +395,10 @@ void AppListView::Dismiss() {
   GetWidget()->Deactivate();
 }
 
+void AppListView::ResetToInitialState() {
+  app_list_main_view_->contents_view()->Back();
+}
+
 void AppListView::SetAppListOverlayVisible(bool visible) {
   DCHECK(overlay_view_);
 

ash/app_list/views/app_list_view.h

@@ -126,6 +126,9 @@ class APP_LIST_EXPORT AppListView : public views::WidgetDelegateView,
   // Dismisses the UI, cleans up and sets the state to CLOSED.
   void Dismiss();
 
+  // Resets the UI to initial state.
+  void ResetToInitialState();
+
   // Enables/disables a semi-transparent overlay over the app list (good for
   // hiding the app list when a modal dialog is being shown).
   void SetAppListOverlayVisible(bool visible);