HSTS: add net-internals UI.

net/base/dns_util.h

Index: net/base/dns_util.h
diff --git a/net/base/dns_util.h b/net/base/dns_util.h
index d86fcb9daf8bde9a7323cbbdc3922a9b52bd7c65..40e8736e00a2573277100738984cd4dffba9c6f0 100644
--- a/net/base/dns_util.h
+++ b/net/base/dns_util.h
@@ -19,6 +19,9 @@ namespace net {
 //   out: a result in DNS form: "\x03www\x06google\x03com\x00"
 bool DNSDomainFromDot(const std::string& dotted, std::string* out);
 
+// DNSDomainToString coverts a domain in DNS format to a dotted string.
+std::string DNSDomainToString(const std::string& domain);
+
 // Returns true iff the given character is in the set of valid DNS label
 // characters as given in RFC 3490, 4.1, 3(a)
 bool IsSTD3ASCIIValidCharacter(char c);