Rename GetNextStreamId to GetNextOutgoingStreamId in QuicSession.

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 912928fdf92f31c49c113b30772d4bcb63e530ab..ba889757fb59fa94f1843b89f7231a608f16d7f8 100644
--- a/net/quic/quic_session_test.cc
+++ b/net/quic/quic_session_test.cc
@@ -128,7 +128,7 @@ class TestSession : public QuicSpdySession {
   TestCryptoStream* GetCryptoStream() override { return &crypto_stream_; }
 
   TestStream* CreateOutgoingDynamicStream() override {
-    TestStream* stream = new TestStream(GetNextStreamId(), this);
+    TestStream* stream = new TestStream(GetNextOutgoingStreamId(), this);
     ActivateStream(stream);
     return stream;
   }