Adding instrumentation to locate the source of jankiness.

content/browser/tcmalloc_internals_request_job.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 "content/browser/tcmalloc_internals_request_job.h"
 
 #include "base/allocator/allocator_extension.h"
+#include "base/profiler/scoped_profile.h"
 #include "content/common/child_process_messages.h"
 #include "content/public/browser/browser_child_process_host_iterator.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/process_type.h"
 #include "net/base/net_errors.h"
 
 namespace content {
 
 // static
@@ skipping 83 matching lines @@
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
       &RequestTcmallocStatsFromChildRenderProcesses));
 }
 #endif
 
 int TcmallocInternalsRequestJob::GetData(
     std::string* mime_type,
     std::string* charset,
     std::string* data,
     const net::CompletionCallback& callback) const {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422489 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422489 TcmallocInternalsRequestJob::GetData"));
+
   mime_type->assign("text/html");
   charset->assign("UTF8");
 
   data->clear();
 #if defined(USE_TCMALLOC)
   AboutTcmalloc(data);
 #endif
   return net::OK;
 }
 
 } // namespace content