Replace calls to set.count() with ContainsKey in QUIC.

net/quic/quic_session_test.cc

Index: net/quic/quic_session_test.cc
diff --git a/net/quic/quic_session_test.cc b/net/quic/quic_session_test.cc
index 7ab6e6efca727b2de4b12741c25283657b452877..9b85143f7bab627a41f05d26bf18eb18facc419c 100644
--- a/net/quic/quic_session_test.cc
+++ b/net/quic/quic_session_test.cc
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/rand_util.h"
+#include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/crypto/crypto_protocol.h"
 #include "net/quic/quic_crypto_stream.h"
@@ -227,7 +228,7 @@ class QuicSessionTest : public ::testing::TestWithParam<QuicVersion> {
 
   void CheckClosedStreams() {
     for (int i = kCryptoStreamId; i < 100; i++) {
-      if (closed_streams_.count(i) == 0) {
+      if (!ContainsKey(closed_streams_, i)) {
         EXPECT_FALSE(session_.IsClosedStream(i)) << " stream id: " << i;
       } else {
         EXPECT_TRUE(session_.IsClosedStream(i)) << " stream id: " << i;