Fix closing namespace comments in //net.

net/ssl/threaded_ssl_private_key.cc

Index: net/ssl/threaded_ssl_private_key.cc
diff --git a/net/ssl/threaded_ssl_private_key.cc b/net/ssl/threaded_ssl_private_key.cc
index 53e8c34d40a0796846a8f42f0dea2d9874030ac6..9e7f9dbd8415f2ca65e43e2e38bdb2bd3eae56a7 100644
--- a/net/ssl/threaded_ssl_private_key.cc
+++ b/net/ssl/threaded_ssl_private_key.cc
@@ -25,7 +25,8 @@ void DoCallback(const base::WeakPtr<ThreadedSSLPrivateKey>& key,
     return;
   callback.Run(error, *signature);
 }
-}
+
+}  // anonymous namespace
 
 class ThreadedSSLPrivateKey::Core
     : public base::RefCountedThreadSafe<ThreadedSSLPrivateKey::Core> {