Implement support for <extensionoptions> embedding in WebUI

chrome/browser/extensions/api/guest_view/guest_view_internal_api.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/guest_view/guest_view_internal_api.h"
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/guest_view_internal.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 22 matching lines @@
   GuestViewManager::WebContentsCreatedCallback callback =
       base::Bind(&GuestViewInternalCreateGuestFunction::CreateGuestCallback,
                  this);
 
   content::WebContents* embedder_web_contents =
       content::WebContents::FromRenderViewHost(render_view_host());
   if (!embedder_web_contents) {
     error_ = "Guest views can only be embedded in web content";
     return false;
   }
+  // If the guest is an <extensionoptions> to be embedded in a WebUI, then
+  // there is no extension, and extension() will be null. Use an empty string
+  // instead.
+  std::string embedder_extension_id;
+  if (extension())
+    embedder_extension_id = extension_id();
 
   guest_view_manager->CreateGuest(view_type,
-                                  extension_id(),
+                                  embedder_extension_id,
                                   embedder_web_contents,
                                   *create_params,
                                   callback);
   return true;
 }
 
 void GuestViewInternalCreateGuestFunction::CreateGuestCallback(
     content::WebContents* guest_web_contents) {
   int guest_instance_id = 0;
   if (guest_web_contents) {
@@ skipping 23 matching lines @@
   guest->SetAutoSize(params->params.enable_auto_size,
                      gfx::Size(params->params.min.width,
                                params->params.min.height),
                      gfx::Size(params->params.max.width,
                                params->params.max.height));
   SendResponse(true);
   return true;
 }
 
 }  // namespace extensions