net: move IsHostnameNonUnique() into url_util.h

net/base/net_util.h

Index: net/base/net_util.h
diff --git a/net/base/net_util.h b/net/base/net_util.h
index 0b7b438eae31c3744b801024816d72afe1c8f171..47c6c0598a64bb85a179e68f39e1d7ff37119623 100644
--- a/net/base/net_util.h
+++ b/net/base/net_util.h
@@ -16,11 +16,6 @@ namespace net {
 
 class AddressList;
 
-// Returns true if |hostname| contains a non-registerable or non-assignable
-// domain name (eg: a gTLD that has not been assigned by IANA) or an IP address
-// that falls in an IANA-reserved range.
-NET_EXPORT bool IsHostnameNonUnique(const std::string& hostname);
-
 // Returns the hostname of the current system. Returns empty string on failure.
 NET_EXPORT std::string GetHostName();