Pick the DTLS handshake timeout based on the ICE RTT estimate

webrtc/base/sslstreamadapter.h

Index: webrtc/base/sslstreamadapter.h
diff --git a/webrtc/base/sslstreamadapter.h b/webrtc/base/sslstreamadapter.h
index 4f5ee02fe44343fb7028e5f9ca354a371ff50d9d..b4f577ae2add967cfe8776ebca75ce823ee496fd 100644
--- a/webrtc/base/sslstreamadapter.h
+++ b/webrtc/base/sslstreamadapter.h
@@ -156,6 +156,11 @@ class SSLStreamAdapter : public StreamAdapterInterface {
   // next lower will be used.
   virtual void SetMaxProtocolVersion(SSLProtocolVersion version) = 0;
 
+  // Set the initial timeout for the handshake message. When the timeout
+  // expires, the handshake message gets retransmitted and the timeout is
+  // exponentially increased.
+  virtual void SetHandshakeTimeout(int timeout_ms) = 0;

[Taylor Brandstetter, 2017/02/02 18:07:41]

nit: Better name would be "InitialRetransmissionTimeout"

[pthatcher2, 2017/02/02 20:09:44]

+1

[skvlad, 2017/02/02 22:19:33]

I made it InitialHandshakeRetransmissionTimeout. Long but accurate.

[Taylor Brandstetter, 2017/02/02 22:57:27]

I'd still call it just "InitialRetransmissionTimeout", since in theory it
applies to any DTLS messages (not just the handshake).

+
   // StartSSL starts negotiation with a peer, whose certificate is verified
   // using the certificate digest. Generally, SetIdentity() and possibly
   // SetServerRole() should have been called before this.