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

net/dns/mapped_host_resolver.cc

Index: net/dns/mapped_host_resolver.cc
diff --git a/net/dns/mapped_host_resolver.cc b/net/dns/mapped_host_resolver.cc
index e102d502444227db01876941a3f093da764ad102..fe1deeb371cb25228007ac6aa8b3ba6c56aa87a4 100644
--- a/net/dns/mapped_host_resolver.cc
+++ b/net/dns/mapped_host_resolver.cc
@@ -23,7 +23,7 @@ int MappedHostResolver::Resolve(const RequestInfo& original_info,
                                 RequestPriority priority,
                                 AddressList* addresses,
                                 const CompletionCallback& callback,
-                                RequestHandle* out_req,
+                                std::unique_ptr<Request>* out_req,
                                 const BoundNetLog& net_log) {
   RequestInfo info = original_info;
   int rv = ApplyRules(&info);
@@ -44,10 +44,6 @@ int MappedHostResolver::ResolveFromCache(const RequestInfo& original_info,
   return impl_->ResolveFromCache(info, addresses, net_log);
 }
 
-void MappedHostResolver::CancelRequest(RequestHandle req) {
-  impl_->CancelRequest(req);
-}
-
 void MappedHostResolver::SetDnsClientEnabled(bool enabled) {
   impl_->SetDnsClientEnabled(enabled);
 }