DNS: Let requests specify a callback for future cache hits

net/dns/host_resolver.cc

Index: net/dns/host_resolver.cc
diff --git a/net/dns/host_resolver.cc b/net/dns/host_resolver.cc
index a7948672aadbda683b84348c510c1e4c5e372d47..1646b8155a45cd91e9f2752f939e7c5711f1033e 100644
--- a/net/dns/host_resolver.cc
+++ b/net/dns/host_resolver.cc
@@ -91,8 +91,23 @@ HostResolver::Options::Options()
 }
 
 HostResolver::RequestInfo::RequestInfo(const HostPortPair& host_port_pair)
-    : host_port_pair_(host_port_pair),
-      address_family_(ADDRESS_FAMILY_UNSPECIFIED),
+    : RequestInfo() {
+  host_port_pair_ = host_port_pair;
+}
+
+HostResolver::RequestInfo::RequestInfo(const RequestInfo& request_info)
+    : host_port_pair_(request_info.host_port_pair_),
+      address_family_(request_info.address_family_),
+      host_resolver_flags_(request_info.host_resolver_flags_),
+      allow_cached_response_(request_info.allow_cached_response_),
+      is_speculative_(request_info.is_speculative_),
+      is_my_ip_address_(request_info.is_my_ip_address_),
+      cache_hit_callback_(request_info.cache_hit_callback_) {}
+
+HostResolver::RequestInfo::~RequestInfo() {}
+
+HostResolver::RequestInfo::RequestInfo()
+    : address_family_(ADDRESS_FAMILY_UNSPECIFIED),
       host_resolver_flags_(0),
       allow_cached_response_(true),
       is_speculative_(false),