Add EarlyChangeCipherSpec tests.

Adapted from patch in https://www.imperialviolet.org/2014/06/05/earlyccs.html.

Change-Id: I14bf314d105780e23e6bd09217870deff5744979
Reviewed-on: https://boringssl-review.googlesource.com/1292
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/common.go b/ssl/test/runner/common.go
index d394b73..8ac76f6 100644
--- a/ssl/test/runner/common.go
+++ b/ssl/test/runner/common.go
@@ -368,6 +368,12 @@
 	// sending the ChangeCipherSpec message (and adjusting cipher
 	// state accordingly for the Finished message).
 	SkipChangeCipherSpec bool
+
+	// EarlyChangeCipherSpec causes the client to send an early
+	// ChangeCipherSpec message before the ClientKeyExchange. A value of
+	// zero disables this behavior. One and two configure variants for 0.9.8
+	// and 1.0.1 modes, respectively.
+	EarlyChangeCipherSpec int
 }
 
 func (c *Config) serverInit() {