Change DTLS default from 1.0 to 1.2 for webrtc.

webrtc/p2p/base/dtlstransport.h

Index: webrtc/p2p/base/dtlstransport.h
diff --git a/webrtc/p2p/base/dtlstransport.h b/webrtc/p2p/base/dtlstransport.h
index e9a1ae2adadb6a361defc8443417eb557666ba94..9f2903e1d7fbbe195d9101acaa8acbaa1472a6aa 100644
--- a/webrtc/p2p/base/dtlstransport.h
+++ b/webrtc/p2p/base/dtlstransport.h
@@ -35,7 +35,7 @@ class DtlsTransport : public Base {
       : Base(name, allocator),
         certificate_(certificate),
         secure_role_(rtc::SSL_CLIENT),
-        ssl_max_version_(rtc::SSL_PROTOCOL_DTLS_10) {}
+        ssl_max_version_(rtc::SSL_PROTOCOL_DTLS_12) {}
 
   ~DtlsTransport() {
     Base::DestroyAllChannels();