Update HTTP/2 NPN/ALPN tokens to "h2-12" to advertise draft 12 support.

net/http/http_response_info.cc

Index: net/http/http_response_info.cc
diff --git a/net/http/http_response_info.cc b/net/http/http_response_info.cc
index 5e0229fbd0495f58c994beff737f25d18deff270..e2da1e7e37e531e971112863cb621fe5ec783dcc 100644
--- a/net/http/http_response_info.cc
+++ b/net/http/http_response_info.cc
@@ -394,9 +394,9 @@ std::string HttpResponseInfo::ConnectionInfoToString(
     case CONNECTION_INFO_SPDY3:
       return "spdy/3";
     case CONNECTION_INFO_SPDY4:
-      // This is the HTTP/2 draft 11 identifier. For internal
+      // This is the HTTP/2 draft 12 identifier. For internal
       // consistency, HTTP/2 is named SPDY4 within Chromium.
-      return "h2-11";
+      return "h2-12";
     case CONNECTION_INFO_QUIC1_SPDY3:
       return "quic/1+spdy/3";
     case NUM_OF_CONNECTION_INFOS: