Update from https://crrev.com/307330

net/ftp/ftp_network_transaction.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/ftp/ftp_network_transaction.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/metrics/histogram.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "net/base/address_list.h"
 #include "net/base/connection_type_histograms.h"
 #include "net/base/escape.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
@@ skipping 344 matching lines @@
   DCHECK(rv != ERR_IO_PENDING);
   DCHECK(!user_callback_.is_null());
 
   // Since Run may result in Read being called, clear callback_ up front.
   CompletionCallback c = user_callback_;
   user_callback_.Reset();
   c.Run(rv);
 }
 
 void FtpNetworkTransaction::OnIOComplete(int result) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/436634 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "436634 FtpNetworkTransaction::OnIOComplete"));
+
   int rv = DoLoop(result);
   if (rv != ERR_IO_PENDING)
     DoCallback(rv);
 }
 
 int FtpNetworkTransaction::ProcessCtrlResponse() {
   FtpCtrlResponse response = ctrl_response_buffer_->PopResponse();
 
   int rv = OK;
   switch (command_sent_) {
@@ skipping 1012 matching lines @@
   if (!had_error_type[type]) {
     had_error_type[type] = true;
     UMA_HISTOGRAM_ENUMERATION("Net.FtpDataConnectionErrorHappened",
         type, NUM_OF_NET_ERROR_TYPES);
   }
   UMA_HISTOGRAM_ENUMERATION("Net.FtpDataConnectionErrorCount",
       type, NUM_OF_NET_ERROR_TYPES);
 }
 
 }  // namespace net