Split ProxyResolverV8Tracing into an implementation and a wrapper.

net/proxy/proxy_resolver.h

 // Copyright (c) 2011 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 NET_PROXY_PROXY_RESOLVER_H_
 #define NET_PROXY_PROXY_RESOLVER_H_
 
 #include "base/callback_forward.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
@@ skipping 11 matching lines @@
 
 // Interface for "proxy resolvers". A ProxyResolver fills in a list of proxies
 // to use for a particular URL. Generally the backend for a ProxyResolver is
 // a PAC script, but it doesn't need to be. ProxyResolver can service multiple
 // requests at a time.
 class NET_EXPORT_PRIVATE ProxyResolver {
  public:
   // Opaque pointer type, to return a handle to cancel outstanding requests.
   typedef void* RequestHandle;
 
-  using LoadStateChangedCallback =
-      base::Callback<void(RequestHandle, LoadState)>;
-
   ProxyResolver() {}
 
   virtual ~ProxyResolver() {}
 
   // Gets a list of proxy servers to use for |url|. If the request will
   // complete asynchronously returns ERR_IO_PENDING and notifies the result
   // by running |callback|.  If the result code is OK then
   // the request was successful and |results| contains the proxy
   // resolution information.  In the case of asynchronous completion
   // |*request| is written to, and can be passed to CancelRequest().
   virtual int GetProxyForURL(const GURL& url,
                              ProxyInfo* results,
                              const CompletionCallback& callback,
                              RequestHandle* request,
                              const BoundNetLog& net_log) = 0;
 
   // Cancels |request|.
   virtual void CancelRequest(RequestHandle request) = 0;
 
   // Gets the LoadState for |request|.
   virtual LoadState GetLoadState(RequestHandle request) const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ProxyResolver);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_RESOLVER_H_