Make infobars ignore button clicks when closing.

chrome/browser/ui/gtk/infobars/confirm_infobar_gtk.cc

Index: chrome/browser/ui/gtk/infobars/confirm_infobar_gtk.cc
===================================================================
--- chrome/browser/ui/gtk/infobars/confirm_infobar_gtk.cc	(revision 102206)
+++ chrome/browser/ui/gtk/infobars/confirm_infobar_gtk.cc	(working copy)
@@ -82,16 +82,22 @@
 }
 
 void ConfirmInfoBarGtk::OnOkButton(GtkWidget* widget) {
+  if (!owned())
+    return;  // We're closing; don't call anything, it might access the owner.
   if (delegate()->AsConfirmInfoBarDelegate()->Accept())
     RemoveSelf();
 }
 
 void ConfirmInfoBarGtk::OnCancelButton(GtkWidget* widget) {
+  if (!owned())
+    return;  // We're closing; don't call anything, it might access the owner.
   if (delegate()->AsConfirmInfoBarDelegate()->Cancel())
     RemoveSelf();
 }
 
 void ConfirmInfoBarGtk::OnLinkClicked(GtkWidget* widget) {
+  if (!owned())
+    return;  // We're closing; don't call anything, it might access the owner.
   if (delegate()->AsConfirmInfoBarDelegate()->LinkClicked(
         gtk_util::DispositionForCurrentButtonPressEvent()))
     RemoveSelf();