Adding instrumentation to locate the source of jankiness.

components/policy/core/common/policy_loader_win.cc

 // Copyright (c) 2014 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 "components/policy/core/common/policy_loader_win.h"
 
 #include <windows.h>
 #include <lm.h>       // For limits.
 #include <ntdsapi.h>  // For Ds[Un]Bind
 #include <rpc.h>      // For struct GUID
@@ skipping 665 matching lines @@
       !machine_policy_watcher_.StartWatching(
           machine_policy_changed_event_.handle(), this)) {
     DLOG(WARNING) << "Failed to start watch for machine policy change event";
     machine_policy_watcher_failed_ = true;
   }
 }
 
 void PolicyLoaderWin::OnObjectSignaled(HANDLE object) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/418183 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION("PolicyLoaderWin_OnObjectSignaled"));
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 PolicyLoaderWin::OnObjectSignaled"));
 
   DCHECK(object == user_policy_changed_event_.handle() ||
          object == machine_policy_changed_event_.handle())
       << "unexpected object signaled policy reload, obj = "
       << std::showbase << std::hex << object;
   Reload(false);
 }
 
 }  // namespace policy