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

extensions/browser/api/dns/dns_api.cc

Index: extensions/browser/api/dns/dns_api.cc
diff --git a/extensions/browser/api/dns/dns_api.cc b/extensions/browser/api/dns/dns_api.cc
index 671254ba4026dc861652631cc4563b53484984f0..c01cb2f0c20bab7cf9040f15eb3911d6c37e60c2 100644
--- a/extensions/browser/api/dns/dns_api.cc
+++ b/extensions/browser/api/dns/dns_api.cc
@@ -25,7 +25,7 @@ namespace extensions {
 DnsResolveFunction::DnsResolveFunction()
     : resource_context_(NULL),
       response_(false),
-      request_handle_(new net::HostResolver::RequestHandle()),
+      request_(),
       addresses_(new net::AddressList) {}
 
 DnsResolveFunction::~DnsResolveFunction() {}
@@ -58,13 +58,11 @@ void DnsResolveFunction::WorkOnIOThread() {
   // determining its answer.
   net::HostPortPair host_port_pair(hostname_, 0);
 
+  std::unique_ptr<net::HostResolver::Request> request;
   net::HostResolver::RequestInfo request_info(host_port_pair);
   int resolve_result = host_resolver->Resolve(
-      request_info,
-      net::DEFAULT_PRIORITY,
-      addresses_.get(),
-      base::Bind(&DnsResolveFunction::OnLookupFinished, this),
-      request_handle_.get(),
+      request_info, net::DEFAULT_PRIORITY, addresses_.get(),
+      base::Bind(&DnsResolveFunction::OnLookupFinished, this), &request,
       net::BoundNetLog());
 
   // Balanced in OnLookupFinished.
@@ -72,6 +70,8 @@ void DnsResolveFunction::WorkOnIOThread() {
 
   if (resolve_result != net::ERR_IO_PENDING)
     OnLookupFinished(resolve_result);
+  if (resolve_result == net::ERR_IO_PENDING)
+    request_ = std::move(request);
 }
 
 void DnsResolveFunction::RespondOnUIThread() {