Re-fix http://crbug.com/87176, and add a test.

content/test/test_render_view_host_factory.h

 // 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.
 
 #ifndef CONTENT_TEST_TEST_RENDER_VIEW_HOST_FACTORY_H_
 #define CONTENT_TEST_TEST_RENDER_VIEW_HOST_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
@@ skipping 19 matching lines @@
   virtual RenderViewHost* CreateRenderViewHost(
       SiteInstance* instance,
       RenderViewHostDelegate* delegate,
       RenderWidgetHostDelegate* widget_delegate,
       int routing_id,
       int main_frame_routing_id,
       bool swapped_out,
       SessionStorageNamespace* session_storage) OVERRIDE;
 
  private:
-  // This is a bit of a hack. With the current design of the site instances /
-  // browsing instances, it's difficult to pass a RenderProcessHostFactory
-  // around properly.
-  //
-  // Instead, we set it right before we create a new RenderViewHost, which
-  // happens before the RenderProcessHost is created. This way, the instance
-  // has the correct factory and creates our special RenderProcessHosts.
-  RenderProcessHostFactory* render_process_host_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(TestRenderViewHostFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_RENDER_VIEW_HOST_FACTORY_H_