Add/resurrect support for bundles of WebStore items.

chrome/browser/extensions/extension_install_prompt.cc

Index: chrome/browser/extensions/extension_install_prompt.cc
diff --git a/chrome/browser/extensions/extension_install_prompt.cc b/chrome/browser/extensions/extension_install_prompt.cc
index 00146cf1364c30d980fbbddfbca2e15075278bb8..bbbeb5888c0b4fd7052c6c1737f21f110c9c0584 100644
--- a/chrome/browser/extensions/extension_install_prompt.cc
+++ b/chrome/browser/extensions/extension_install_prompt.cc
@@ -942,8 +942,9 @@ void ExtensionInstallPrompt::ShowConfirmation() {
                                    REGULAR_PERMISSIONS);
 
     scoped_refptr<const extensions::PermissionSet> withheld =
-        extension_->permissions_data()->withheld_permissions();
-    if (!withheld->IsEmpty()) {
+        extension_ ? extension_->permissions_data()->withheld_permissions()
+                   : nullptr;
+    if (withheld && !withheld->IsEmpty()) {
       prompt_->SetPermissions(
           message_provider->GetWarningMessages(withheld.get(), type),
           PermissionsType::WITHHELD_PERMISSIONS);