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

extensions/browser/api/sockets_udp/sockets_udp_api.cc

Index: extensions/browser/api/sockets_udp/sockets_udp_api.cc
diff --git a/extensions/browser/api/sockets_udp/sockets_udp_api.cc b/extensions/browser/api/sockets_udp/sockets_udp_api.cc
index 9e2e607a4bdcef3cf4ea9e7a724f5f38ba095634..ca1600c1c4fc9fbc8c6613b7f1547594bc832be5 100644
--- a/extensions/browser/api/sockets_udp/sockets_udp_api.cc
+++ b/extensions/browser/api/sockets_udp/sockets_udp_api.cc
@@ -251,6 +251,10 @@ void SocketsUdpSendFunction::AfterDnsLookup(int lookup_result) {
   } else {
     SetSendResult(lookup_result, -1);
   }
+
+  // TODO(maksims): investigate why std::unique_ptr<HostResolver::Request>'s
+  // destructor is not called automatically.
+  request_handle_.reset();
 }
 
 void SocketsUdpSendFunction::StartSendTo() {