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 670d23e377917f74199251caaa445ef9f5b25f30..ee181e0b1b6fa4e597236000433050a56eafc8b2 100644
--- a/chrome/browser/extensions/extension_install_prompt.cc
+++ b/chrome/browser/extensions/extension_install_prompt.cc
@@ -937,8 +937,9 @@ 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->GetLegacyWarningMessages(withheld.get(), type),
           PermissionsType::WITHHELD_PERMISSIONS);