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"
@@ skipping 350 matching lines @@
   // 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()) {
+    // TODO(vadimt): Remove ScopedProfile below once crbug.com/424359 is fixed.
+    tracked_objects::ScopedProfile tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "424359 HttpStreamParser::OnIOComplete callback"));
+
     CompletionCallback c = callback_;
     callback_.Reset();
     c.Run(result);
   }
 }
 
 int HttpStreamParser::DoLoop(int result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/424359 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("424359 HttpStreamParser::DoLoop"));
+
   do {
     DCHECK_NE(ERR_IO_PENDING, result);
     DCHECK_NE(STATE_DONE, io_state_);
     DCHECK_NE(STATE_NONE, io_state_);
     State state = io_state_;
     io_state_ = STATE_NONE;
     switch (state) {
       case STATE_SEND_HEADERS:
         DCHECK_EQ(OK, result);
         result = DoSendHeaders();
@@ skipping 663 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