Change HostResolver::Resolve() to take an std::unique_ptr<Request>* rather than a RequestHandle*

net/dns/host_resolver_impl.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 NET_DNS_HOST_RESOLVER_IMPL_H_
 #define NET_DNS_HOST_RESOLVER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 118 matching lines @@
   // HostResolverProc from ProcTaskParams will be queried. If the DnsClient is
   // not pre-configured with a valid DnsConfig, a new config is fetched from
   // NetworkChangeNotifier.
   void SetDnsClient(std::unique_ptr<DnsClient> dns_client);
 
   // HostResolver methods:
   int Resolve(const RequestInfo& info,
               RequestPriority priority,
               AddressList* addresses,
               const CompletionCallback& callback,
-              RequestHandle* out_req,
+              std::unique_ptr<Request>* out_req,
               const BoundNetLog& source_net_log) override;
-  void ChangeRequestPriority(RequestHandle req,
-                             RequestPriority priority) override;
-  void CancelRequest(RequestHandle req) override;
   int ResolveFromCache(const RequestInfo& info,
                        AddressList* addresses,
                        const BoundNetLog& source_net_log) override;
   void SetDnsClientEnabled(bool enabled) override;
   HostCache* GetHostCache() override;
   std::unique_ptr<base::Value> GetDnsConfigAsValue() const override;
 
   // Like |ResolveFromCache()|, but can return a stale result if the
   // implementation supports it. Fills in |*stale_info| if a response is
   // returned to indicate how stale (or not) it is.
@@ skipping 15 matching lines @@
 
   // Callback from HaveOnlyLoopbackAddresses probe.
   void SetHaveOnlyLoopbackAddresses(bool result);
 
  private:
   friend class HostResolverImplTest;
   class Job;
   class ProcTask;
   class LoopbackProbeJob;
   class DnsTask;
-  class Request;
+  class RequestImpl;
   typedef HostCache::Key Key;
   typedef std::map<Key, Job*> JobMap;
 
   // Number of consecutive failures of DnsTask (with successful fallback to
   // ProcTask) before the DnsClient is disabled until the next DNS change.
   static const unsigned kMaximumDnsFailures;
 
   // Helper used by |Resolve()| and |ResolveFromCache()|.  Performs IP
   // literal, cache and HOSTS lookup (if enabled), returns OK if successful,
   // ERR_NAME_NOT_RESOLVED if either hostname is invalid or IP literal is
@@ skipping 178 matching lines @@
 // This function is only exposed so it can be unit-tested.
 // TODO(tfarina): It would be better to change the tests so this function
 // gets exercised indirectly through HostResolverImpl.
 NET_EXPORT_PRIVATE bool ResolveLocalHostname(base::StringPiece host,
                                              uint16_t port,
                                              AddressList* address_list);
 
 }  // namespace net
 
 #endif  // NET_DNS_HOST_RESOLVER_IMPL_H_