Update from https://crrev.com/306655

net/url_request/view_cache_helper.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/url_request/view_cache_helper.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/strings/stringprintf.h"
 #include "net/base/escape.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_response_info.h"
 #include "net/url_request/url_request_context.h"
 
@@ skipping 336 matching lines @@
     next_state_ = STATE_READ_DATA;
   } else {
     data_->append(VIEW_CACHE_TAIL);
     entry_->Close();
     entry_ = NULL;
   }
   return OK;
 }
 
 void ViewCacheHelper::OnIOComplete(int result) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 ViewCacheHelper::OnIOComplete"));
+
   DoLoop(result);
 }
 
 }  // namespace net.