Give the main frame a RenderWidget.

content/browser/renderer_host/render_view_host_factory.cc

 // Copyright (c) 2012 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/renderer_host/render_view_host_factory.h"
 
 #include "base/logging.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 
 namespace content {
 
 // static
 RenderViewHostFactory* RenderViewHostFactory::factory_ = NULL;
 
 // static
 RenderViewHost* RenderViewHostFactory::Create(
     SiteInstance* instance,
     RenderViewHostDelegate* delegate,
     RenderWidgetHostDelegate* widget_delegate,
     int32 routing_id,
     int32 main_frame_routing_id,
     bool swapped_out,
     bool hidden) {
+  // TODO(dcheng): Once the main frame's RenderWidgetHost is used for painting,
+  // the surface creation/lookup here can be removed and the values hardcoded to
+  // 0. https://crbug.com/526958
   int32 surface_id;
   // RenderViewHost creation can be either browser-driven (by the user opening a
   // new tab) or renderer-driven (by script calling window.open, etc).
   //
   // In the browser-driven case, the routing ID of the view is lazily assigned:
   // this is signified by passing MSG_ROUTING_NONE for |routing_id|.
   if (routing_id == MSG_ROUTING_NONE) {
     routing_id = instance->GetProcess()->GetNextRoutingID();
     // No surface has yet been created for the RVH.
     surface_id = GpuSurfaceTracker::Get()->AddSurfaceForRenderer(
@@ skipping 24 matching lines @@
   factory_ = factory;
 }
 
 // static
 void RenderViewHostFactory::UnregisterFactory() {
   DCHECK(factory_) << "No factory to unregister.";
   factory_ = NULL;
 }
 
 }  // namespace content