Remove SPDY 2.1 support.

net/http/http_stream_factory.h

Index: net/http/http_stream_factory.h
diff --git a/net/http/http_stream_factory.h b/net/http/http_stream_factory.h
index f7678446535fc57e1e25282d0ebc8806bc53bae0..58efdf39d6ea5b24c32ea97a20dc00d50057b673 100644
--- a/net/http/http_stream_factory.h
+++ b/net/http/http_stream_factory.h
@@ -230,21 +230,14 @@ class NET_EXPORT HttpStreamFactory {
   // Check if a HostPortPair is excluded from using spdy.
   static bool HasSpdyExclusion(const HostPortPair& endpoint);
 
-  // Sets http/1.1 and spdy/2 (the default spdy protocol) as the protocols
-  // supported.
-  static void EnableNpnSpdy();
-
-  // Sets http/1.1 as the protocols supported.
+  // Sets http/1.1 as the only protocol supported via NPN.
   static void EnableNpnHttpOnly();
 
-  // Sets http/1.1, spdy/2 and spdy/2.1 as the protocols supported.
-  // If flow-control is enabled, received WINDOW_UPDATE and SETTINGS messages
-  // are processed and outstanding window size is actually obeyed when sending
-  // data frames, and WINDOW_UPDATE messages are generated when data is
-  // consumed.
-  static void EnableFlowControl();
+  // Sets http/1.1 and spdy/2 (the default spdy protocol) as the protocols
+  // supported via NPN.
+  static void EnableNpnSpdy();
 
-  // Sets http/1.1, spdy/2, spdy/2.1 and spdy/3 as the protocols supported.
+  // Sets http/1.1, spdy/2, and spdy/3 as the protocols supported via NPN.
   static void EnableNpnSpdy3();
 
   // Sets the protocols supported by NPN (next protocol negotiation) during the