Adding instrumentation to locate the source of jankiness.

net/http/http_stream_parser.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/http/http_stream_parser.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
 #include "net/base/io_buffer.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/upload_data_stream.h"
 #include "net/http/http_chunked_decoder.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_request_info.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_util.h"
@@ skipping 330 matching lines @@
   io_state_ = STATE_READ_BODY;
 
   int result = DoLoop(OK);
   if (result == ERR_IO_PENDING)
     callback_ = callback;
 
   return result;
 }
 
 void HttpStreamParser::OnIOComplete(int result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 DidCompleteReadWrite => HttpStreamParser::OnIOComplete"));
+
   result = DoLoop(result);
 
   // The client callback can do anything, including destroying this class,
   // so any pending callback must be issued after everything else is done.
   if (result != ERR_IO_PENDING && !callback_.is_null()) {
     CompletionCallback c = callback_;
     callback_.Reset();
     c.Run(result);
   }
 }
@@ skipping 675 matching lines @@
       request_body->IsInMemory() &&
       request_body->size() > 0) {
     size_t merged_size = request_headers.size() + request_body->size();
     if (merged_size <= kMaxMergedHeaderAndBodySize)
       return true;
   }
   return false;
 }
 
 }  // namespace net