Move ProxyConfigService construction onto the IO thread.

content/shell/shell_resource_context.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_SHELL_SHELL_RESOURCE_CONTEXT_H_
 #define CONTENT_SHELL_SHELL_RESOURCE_CONTEXT_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "content/public/browser/resource_context.h"
 
 namespace content {
 
 class ShellURLRequestContextGetter;
 
 class ShellResourceContext : public ResourceContext {
  public:
   explicit ShellResourceContext(ShellURLRequestContextGetter* getter);
   virtual ~ShellResourceContext();
 
+  void StartTearDown();
+
  private:
   // ResourceContext implementation:
   virtual net::HostResolver* GetHostResolver() OVERRIDE;
   virtual net::URLRequestContext* GetRequestContext() OVERRIDE;
 
   scoped_refptr<ShellURLRequestContextGetter> getter_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellResourceContext);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_SHELL_RESOURCE_CONTEXT_H_