relnote: Protected by --quic_fix_beta_last_max. Fix conservative decrease for n-connection emulatio…

net/quic/core/congestion_control/cubic_bytes.h

Index: net/quic/core/congestion_control/cubic_bytes.h
diff --git a/net/quic/core/congestion_control/cubic_bytes.h b/net/quic/core/congestion_control/cubic_bytes.h
index 9775f212d42d1d90ed86fede3a920a3e8aa9ccd4..c205cef05e50e75a81690f8d6d9747a549a0676d 100644
--- a/net/quic/core/congestion_control/cubic_bytes.h
+++ b/net/quic/core/congestion_control/cubic_bytes.h
@@ -50,10 +50,21 @@ class QUIC_EXPORT_PRIVATE CubicBytes {
   // window. Resets Cubic state during quiescence.
   void OnApplicationLimited();
 
+  // If true, enable the fix for the convex-mode signing bug.  See
+  // b/32170105 for more information about the bug.
+  // TODO(jokulik):  Remove once the fix is enabled by default.
   void SetFixConvexMode(bool fix_convex_mode);
 
+  // If true, fix CubicBytes quantization bug.  See b/33273459 for
+  // more information about the bug.
+  // TODO(jokulik): Remove once the fix is enabled by default.
   void SetFixCubicQuantization(bool fix_cubic_quantization);
 
+  // If true, enable the fix for scaling BetaLastMax for n-nonnection
+  // emulation.  See b/33272010 for more information about the bug.
+  // TODO(jokulik):  Remove once the fix is enabled by default.
+  void SetFixBetaLastMax(bool fix_beta_last_max);
+
  private:
   friend class test::CubicBytesTest;
 
@@ -61,10 +72,15 @@ class QUIC_EXPORT_PRIVATE CubicBytes {
     return QuicTime::Delta::FromMilliseconds(30);
   }
 
-  // Compute the TCP Cubic alpha and beta based on the current number of
-  // connections.
+  // Compute the TCP Cubic alpha, beta, and beta-last-max based on the
+  // current number of connections.
   float Alpha() const;
   float Beta() const;
+  float BetaLastMax() const;
+
+  QuicByteCount last_max_congestion_window() const {
+    return last_max_congestion_window_;
+  }
 
   const QuicClock* clock_;
 
@@ -108,6 +124,10 @@ class QUIC_EXPORT_PRIVATE CubicBytes {
   // TODO(jokulik):  Remove once the experiment is done.
   bool fix_cubic_quantization_;
 
+  // Fix beta last max for n-connection-emulation.
+  // TODO(jokulik):  Remove once the corresponding experiment is done.
+  bool fix_beta_last_max_;
+
   DISALLOW_COPY_AND_ASSIGN(CubicBytes);
 };