Fix MSAN failure due to reading from an uninitialized variable. No functional change (the variable …

net/quic/core/congestion_control/bbr_sender.cc

Index: net/quic/core/congestion_control/bbr_sender.cc
diff --git a/net/quic/core/congestion_control/bbr_sender.cc b/net/quic/core/congestion_control/bbr_sender.cc
index d8ab1cef8e719312d21c8becd7f6b64ed3328c34..04908c22f164ef21e946da6c2d2f21f439dddb24 100644
--- a/net/quic/core/congestion_control/bbr_sender.cc
+++ b/net/quic/core/congestion_control/bbr_sender.cc
@@ -98,7 +98,8 @@ BbrSender::BbrSender(const QuicClock* clock,
       probe_rtt_round_passed_(false),
       last_sample_is_app_limited_(false),
       recovery_state_(NOT_IN_RECOVERY),
-      end_recovery_at_(0) {
+      end_recovery_at_(0),
+      recovery_window_(max_congestion_window_) {
   EnterStartupMode();
 }