Fix a QUIC flow control bug where a stream is flow control blocked when

net/quic/quic_flow_controller.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_QUIC_FLOW_CONTROLLER_H_
 #define NET_QUIC_QUIC_FLOW_CONTROLLER_H_
 
 #include "base/basictypes.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
@@ skipping 29 matching lines @@
   bool UpdateHighestReceivedOffset(uint64 new_offset);
 
   // Called when bytes received from the peer are consumed locally. This may
   // trigger the sending of a WINDOW_UPDATE frame using |connection|.
   void AddBytesConsumed(uint64 bytes_consumed);
 
   // Called when bytes are sent to the peer.
   void AddBytesSent(uint64 bytes_sent);
 
   // Set a new send window offset.
-  // Returns true if this changes send_window_offset_, and false in the case
-  // where |new_send_window| is <= send_window_offset_.
+  // Returns true if this increases send_window_offset_ and is now blocked.
   bool UpdateSendWindowOffset(uint64 new_send_window_offset);
 
   // Returns the current available send window.
   uint64 SendWindowSize() const;
 
   // Send a BLOCKED frame if appropriate.
   void MaybeSendBlocked();
 
   // Disable flow control.
   void Disable();
@@ skipping 59 matching lines @@
   // Keep track of the last time we sent a BLOCKED frame. We should only send
   // another when the number of bytes we have sent has changed.
   uint64 last_blocked_send_window_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicFlowController);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_FLOW_CONTROLLER_H_