Improve test coverage around NewSessionTicket message.

Test both when the peer doesn't support session tickets and when the server
promises a NewSessionTicket message but doesn't deliver.

Change-Id: I48f338094002beac2e6b80e41851c72822b3b9d5
Reviewed-on: https://boringssl-review.googlesource.com/1300
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/common.go b/ssl/test/runner/common.go
index 8ac76f6..7319463 100644
--- a/ssl/test/runner/common.go
+++ b/ssl/test/runner/common.go
@@ -374,6 +374,10 @@
 	// zero disables this behavior. One and two configure variants for 0.9.8
 	// and 1.0.1 modes, respectively.
 	EarlyChangeCipherSpec int
+
+	// SkipNewSessionTicket causes the server to skip sending the
+	// NewSessionTicket message despite promising to in ServerHello.
+	SkipNewSessionTicket bool
 }
 
 func (c *Config) serverInit() {