Fix QuicHttpStream reporting negative sent bytes.

net/quic/chromium/quic_http_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/quic/chromium/quic_http_stream.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/callback_helpers.h"
@@ skipping 590 matching lines @@
 
 int QuicHttpStream::DoSendHeaders() {
   // Log the actual request with the URL Request's net log.
   stream_net_log_.AddEvent(
       NetLogEventType::HTTP_TRANSACTION_QUIC_SEND_REQUEST_HEADERS,
       base::Bind(&QuicRequestNetLogCallback, stream_->id(), &request_headers_,
                  priority_));
   bool has_upload_data = request_body_stream_ != nullptr;
 
   next_state_ = STATE_SEND_HEADERS_COMPLETE;
-  size_t frame_len = stream_->WriteHeaders(std::move(request_headers_),
-                                           !has_upload_data, nullptr);
-  headers_bytes_sent_ += frame_len;
+  int rv = stream_->WriteHeaders(std::move(request_headers_), !has_upload_data,
+                                 nullptr);
+  if (rv > 0)
+    headers_bytes_sent_ += rv;
 
   request_headers_ = SpdyHeaderBlock();
-  return static_cast<int>(frame_len);
+  return rv;
 }
 
 int QuicHttpStream::DoSendHeadersComplete(int rv) {
   if (rv < 0)
     return rv;
 
   next_state_ = request_body_stream_ ? STATE_READ_REQUEST_BODY : STATE_OPEN;
 
   return OK;
 }
@@ skipping 177 matching lines @@
   // Explicit stream error are always fatal.
   if (stream_->stream_error() != QUIC_STREAM_NO_ERROR &&
       stream_->stream_error() != QUIC_STREAM_CONNECTION_ERROR) {
     return ERR_QUIC_PROTOCOL_ERROR;
   }
 
   return ERR_QUIC_PROTOCOL_ERROR;
 }
 
 }  // namespace net