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 be393b047e433495cd453cbe02c6c7bb55bbfcb9..a7d9b21e7b3af9ac01af552ed8e5df7abdf83f65 100644
--- a/net/dns/host_resolver.cc
+++ b/net/dns/host_resolver.cc
@@ -98,6 +98,24 @@ HostResolver::RequestInfo::RequestInfo(const HostPortPair& host_port_pair)
       is_speculative_(false),
       is_my_ip_address_(false) {}
 
+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),
+      is_my_ip_address_(false) {}
+
 HostResolver::~HostResolver() {
 }