Update the comment for QUIC BBRv2's startup_cwnd_gain.

PiperOrigin-RevId: 457542351

quiche/quic/core/congestion_control/bbr2_misc.h

diff --git a/quiche/quic/core/congestion_control/bbr2_misc.h b/quiche/quic/core/congestion_control/bbr2_misc.h
index cbfc2bd..66b5764 100644
--- a/quiche/quic/core/congestion_control/bbr2_misc.h
+++ b/quiche/quic/core/congestion_control/bbr2_misc.h
@@ -75,7 +75,7 @@
    * STARTUP parameters.
    */
 
-  // The gain for both CWND and PacingRate at startup.
+  // The gain for CWND in startup.
   float startup_cwnd_gain = 2.0;
   // TODO(wub): Maybe change to the newly derived value of 2.773 (4 * ln(2)).
   float startup_pacing_gain = 2.885;