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

net/quic/quic_flow_controller.cc

 // 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.
 
 #include "net/quic/quic_flow_controller.h"
 
 #include "base/basictypes.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/quic_protocol.h"
@@ skipping 145 matching lines @@
     return false;
   }
 
   // Only update if send window has increased.
   if (new_send_window_offset <= send_window_offset_) {
     return false;
   }
 
   DVLOG(1) << ENDPOINT << "UpdateSendWindowOffset for stream " << id_
            << " with new offset " << new_send_window_offset
-           << " , current offset: " << send_window_offset_;
+           << " current offset: " << send_window_offset_
+           << " bytes_sent: " << bytes_sent_;
 
+  const bool blocked = IsBlocked();
   send_window_offset_ = new_send_window_offset;
-  return true;
+  return blocked;
 }
 
 void QuicFlowController::Disable() {
   is_enabled_ = false;
 }
 
 bool QuicFlowController::IsEnabled() const {
   return is_enabled_;
 }
 
 bool QuicFlowController::IsBlocked() const {
   return IsEnabled() && SendWindowSize() == 0;
 }
 
 uint64 QuicFlowController::SendWindowSize() const {
   if (bytes_sent_ > send_window_offset_) {
     return 0;
   }
   return send_window_offset_ - bytes_sent_;
 }
 
 }  // namespace net