Parent the AppInfoDialog using a ModalDialogHost

ui/app_list/views/app_list_view.h

Index: ui/app_list/views/app_list_view.h
diff --git a/ui/app_list/views/app_list_view.h b/ui/app_list/views/app_list_view.h
index 66b9189e28caf339183ebfeb6c688a8c3995e414..9649bb7cd4a546df3e51927d1b965a17b30c3abf 100644
--- a/ui/app_list/views/app_list_view.h
+++ b/ui/app_list/views/app_list_view.h
@@ -26,6 +26,10 @@ namespace views {
 class ImageView;
 }
 
+namespace web_modal {
+class ModalDialogHost;
+}
+
 namespace app_list {
 class ApplicationDragAndDropHost;
 class AppListMainView;
@@ -121,6 +125,8 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDelegateView,
   // Gets the PaginationModel owned by this view's apps grid.
   PaginationModel* GetAppsPaginationModel();
 
+  web_modal::ModalDialogHost* GetDialogHost();
+
  private:
   friend class ::test::AppListViewTestApi;