Fix flow control enforcement condition.

net/spdy/spdy_stream.cc

 // Copyright (c) 2012 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/spdy/spdy_stream.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 329 matching lines @@
         stream_id_, static_cast<uint32>(unacked_recv_window_bytes_));
     unacked_recv_window_bytes_ = 0;
   }
 }
 
 void SpdyStream::DecreaseRecvWindowSize(int32 delta_window_size) {
   DCHECK(session_->IsStreamActive(stream_id_));
   DCHECK_GE(session_->flow_control_state(), SpdySession::FLOW_CONTROL_STREAM);
   DCHECK_GE(delta_window_size, 1);
 
-  // Since we never decrease the initial receive window size,
-  // |delta_window_size| should never cause |recv_window_size_| to go
-  // negative. If we do, the receive window isn't being respected.
-  if (delta_window_size > recv_window_size_) {
+  // The receiving window size as the peer knows it is
+  // |recv_window_size_ - unacked_recv_window_bytes_|, if more data are sent by
+  // the peer, that means that the receive window is not being respected.
+  if (delta_window_size > recv_window_size_ - unacked_recv_window_bytes_) {
     session_->ResetStream(
-        stream_id_, RST_STREAM_PROTOCOL_ERROR,
+        stream_id_, RST_STREAM_FLOW_CONTROL_ERROR,
         "delta_window_size is " + base::IntToString(delta_window_size) +
             " in DecreaseRecvWindowSize, which is larger than the receive " +
             "window size of " + base::IntToString(recv_window_size_));
     return;
   }
 
   recv_window_size_ -= delta_window_size;
   net_log_.AddEvent(
       NetLog::TYPE_HTTP2_STREAM_UPDATE_RECV_WINDOW,
       base::Bind(&NetLogSpdyStreamWindowUpdateCallback, stream_id_,
@@ skipping 562 matching lines @@
       description = base::StringPrintf("Unknown state 0x%08X (%u)", state,
                                        state);
       break;
   }
   return description;
 }
 
 #undef STATE_CASE
 
 }  // namespace net