Preparation steps for adding speculative renderer creation.

content/browser/frame_host/frame_tree.cc

 // Copyright 2013 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 "content/browser/frame_host/frame_tree.h"
 
 #include <queue>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 188 matching lines @@
     FrameTreeNode* source,
     SiteInstance* site_instance) {
   // Create the swapped out RVH for the new SiteInstance. This will create
   // a top-level swapped out RFH as well, which will then be wrapped by a
   // RenderFrameProxyHost.
   if (!source->IsMainFrame()) {
     RenderViewHostImpl* render_view_host =
         source->frame_tree()->GetRenderViewHost(site_instance);
     if (!render_view_host) {
       root()->render_manager()->CreateRenderFrame(
-          site_instance, MSG_ROUTING_NONE,
-          CREATE_RF_SWAPPED_OUT | CREATE_RF_HIDDEN);
+          site_instance, nullptr, MSG_ROUTING_NONE,
+          CREATE_RF_SWAPPED_OUT | CREATE_RF_HIDDEN, nullptr);
     }
   }
 
   scoped_refptr<SiteInstance> instance(site_instance);
 
   // Proxies are created in the FrameTree in response to a node navigating to a
   // new SiteInstance. Since |source|'s navigation will replace the currently
   // loaded document, the entire subtree under |source| will be removed.
   ForEach(base::Bind(&CreateProxyForSiteInstance, instance), source);
 }
@@ skipping 126 matching lines @@
         rvh->Shutdown();
         render_view_host_pending_shutdown_map_.erase(multi_iter);
       }
       break;
     }
     CHECK(render_view_host_found);
   }
 }
 
 }  // namespace content