Certificate Transparency: Notify STH Observers of known STHs

net/cert/signed_tree_head.h

Index: net/cert/signed_tree_head.h
diff --git a/net/cert/signed_tree_head.h b/net/cert/signed_tree_head.h
index 154c7a9d08dad187e5b83e9ed238f579ace36845..2d65192fc542624b5a2b7a193d4b9a85e0e4c643 100644
--- a/net/cert/signed_tree_head.h
+++ b/net/cert/signed_tree_head.h
@@ -52,6 +52,11 @@ struct NET_EXPORT SignedTreeHead {
 
 NET_EXPORT void PrintTo(const SignedTreeHead& sth, std::ostream* os);
 
+NET_EXPORT bool operator==(const SignedTreeHead& lhs,
+                           const SignedTreeHead& rhs);
+NET_EXPORT bool operator!=(const SignedTreeHead& lhs,
+                           const SignedTreeHead& rhs);
+
 }  // namespace ct
 
 }  // namespace net