Allow cert-popup for WebView guests.

components/constrained_window/constrained_window_views.cc

Index: components/constrained_window/constrained_window_views.cc
diff --git a/components/constrained_window/constrained_window_views.cc b/components/constrained_window/constrained_window_views.cc
index d00551385504274b22bd5666e1d1d8496dd99168..5b957458922acb1ae3a4154099370242bc5ab938 100644
--- a/components/constrained_window/constrained_window_views.cc
+++ b/components/constrained_window/constrained_window_views.cc
@@ -130,6 +130,15 @@ void UpdateWidgetModalDialogPosition(views::Widget* widget,
                             widget->GetRootView()->GetPreferredSize());
 }
 
+bool HasTopLevelDialogManager(content::WebContents* web_contents) {
+  // For embedded WebContents, use the embedder's WebContents for constrained
+  // window.
+  content::WebContents* top_level_web_contents =
+      guest_view::GuestViewBase::GetTopLevelWebContents(web_contents);
+  return web_modal::WebContentsModalDialogManager::FromWebContents(
+             top_level_web_contents) != nullptr;
+}
+
 views::Widget* ShowWebModalDialogViews(
     views::WidgetDelegate* dialog,
     content::WebContents* initiator_web_contents) {