[SPDY] Add flag and about:flags entry for SPDY/4 alpha 1

net/http/http_network_transaction_spdy3_unittest.cc

Index: net/http/http_network_transaction_spdy3_unittest.cc
diff --git a/net/http/http_network_transaction_spdy3_unittest.cc b/net/http/http_network_transaction_spdy3_unittest.cc
index 9a930da30f8a55ca4affc1be9e08517fc17df1c8..b9a2e5c638c8173951ef6de01116ed29a21352d1 100644
--- a/net/http/http_network_transaction_spdy3_unittest.cc
+++ b/net/http/http_network_transaction_spdy3_unittest.cc
@@ -104,7 +104,8 @@ std::vector<std::string> MakeNextProtos(const char* a, ...) {
 // SpdyNextProtos returns a vector of NPN protocol strings for negotiating
 // SPDY.
 std::vector<std::string> SpdyNextProtos() {
-  return MakeNextProtos("http/1.1", "spdy/2", "spdy/3", "spdy/3.1", NULL);
+  return MakeNextProtos("http/1.1", "spdy/2", "spdy/3", "spdy/3.1",
+                        "spdy/4a1", NULL);
 }
 
 int GetIdleSocketCountInTransportSocketPool(net::HttpNetworkSession* session) {
@@ -9691,7 +9692,8 @@ TEST_F(HttpNetworkTransactionSpdy3Test, SpdyAlternateProtocolThroughProxy) {
   HttpStreamFactory::set_use_alternate_protocols(true);
   HttpStreamFactory::SetNextProtos(
       MakeNextProtos(
-          "http/1.1", "http1.1", "spdy/2", "spdy/3", "spdy/3.1", "spdy", NULL));
+          "http/1.1", "http1.1", "spdy/2", "spdy/3", "spdy/3.1",
+          "spdy/4a1", "spdy", NULL));
 
   SpdySessionDependencies session_deps(
       ProxyService::CreateFixedFromPacResult("PROXY myproxy:70"));