Change ProxyResolver::GetProxyForURL() to take a scoped_ptr<Request>* rather than a RequestHandle*

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/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "net/base/completion_callback.h"
 #include "net/base/load_states.h"
 #include "net/base/net_export.h"
 #include "net/proxy/proxy_resolver_script_data.h"
 #include "url/gurl.h"
 
 namespace net {
 
 class BoundNetLog;
 class ProxyInfo;
 
 // 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;
+  class Request {
+   public:
+    virtual ~Request() {}  // Cancels the request
+    virtual LoadState GetLoadState() = 0;
+  };
 
   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().
+  // |*request| is written to. Call request->reset() to cancel. The
+  // scoped_ptr<Request> must not outlive the ProxyResolver that assigned it.
   virtual int GetProxyForURL(const GURL& url,
                              ProxyInfo* results,
                              const CompletionCallback& callback,
-                             RequestHandle* request,
+                             scoped_ptr<Request>* 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_