Check if BubbleReference weak pointer is valid before using it in the chooser

chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc

Index: chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
diff --git a/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc b/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
index 0449d75b178e2b069b7cd9f968b2e06cdf6b4ba1..f7a2ee07dc4a11d52011f06b0b64fe6cebb0a8c2 100644
--- a/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
+++ b/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
@@ -129,13 +129,15 @@ views::View* ChooserBubbleUiViewDelegate::CreateFootnoteView() {
 
 bool ChooserBubbleUiViewDelegate::Accept() {
   chooser_content_view_->Accept();
-  bubble_reference_->CloseBubble(BUBBLE_CLOSE_ACCEPTED);
+  if (bubble_reference_)
+    bubble_reference_->CloseBubble(BUBBLE_CLOSE_ACCEPTED);
   return true;
 }
 
 bool ChooserBubbleUiViewDelegate::Cancel() {
   chooser_content_view_->Cancel();
-  bubble_reference_->CloseBubble(BUBBLE_CLOSE_CANCELED);
+  if (bubble_reference_)
+    bubble_reference_->CloseBubble(BUBBLE_CLOSE_CANCELED);
   return true;
 }