Unwind the SSL connection holdback experiment and remove related code

net/socket/ssl_session_cache_openssl.h

Index: net/socket/ssl_session_cache_openssl.h
diff --git a/net/socket/ssl_session_cache_openssl.h b/net/socket/ssl_session_cache_openssl.h
index abf5eab78cbe9393eabdaca83c067edbd2c045dd..bbd9659641df062dc870880f805031006deddb59 100644
--- a/net/socket/ssl_session_cache_openssl.h
+++ b/net/socket/ssl_session_cache_openssl.h
@@ -113,9 +113,6 @@ class NET_EXPORT SSLSessionCacheOpenSSL {
   // Return true iff a cached session was associated with the |ssl| connection.
   bool SetSSLSessionWithKey(SSL* ssl, const std::string& cache_key);
 
-  // Return true iff a cached session was associated with the given |cache_key|.
-  bool SSLSessionIsInCache(const std::string& cache_key) const;
-
   // Indicates that the SSL session associated with |ssl| is "good" - that is,
   // that all associated cryptographic parameters that were negotiated,
   // including the peer's certificate, were successfully validated. Because