Merge GetOrCreateDynamicStream() into GetOrCreateStream().

GetOrCreateDynamicStream() no longer guarantees that the returned stream is non-static. And since we have a single stream map for all streams, we can just have one method.

gfe-relnote: Protected by quic_inline_getorcreatedynamicstream.
PiperOrigin-RevId: 258426677
Change-Id: I89ac704a44da79afce3c1704efd5d721c9585f32
diff --git a/quic/core/quic_session.h b/quic/core/quic_session.h
index 5ef497d..24060e8 100644
--- a/quic/core/quic_session.h
+++ b/quic/core/quic_session.h
@@ -370,6 +370,7 @@
   // such stream exists, and |stream_id| is a peer-created stream id,
   // then a new stream is created and returned. In all other cases, nullptr is
   // returned.
+  // Caller does not own the returned stream.
   QuicStream* GetOrCreateStream(const QuicStreamId stream_id);
 
   // Mark a stream as draining.
@@ -475,6 +476,8 @@
   // returned. However if |stream_id| is a locally-created id and no such stream
   // exists, the connection is closed.
   // Caller does not own the returned stream.
+  // TODO(renjietang): Remove this method after
+  // quic_inline_getorcreatedynamicstream is deprecated.
   QuicStream* GetOrCreateDynamicStream(QuicStreamId stream_id);
 
   // Performs the work required to close |stream_id|.  If |locally_reset|