Adding instrumentation to locate the source of jankiness.

base/synchronization/waitable_event_watcher_win.cc

 // Copyright (c) 2011 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 "base/synchronization/waitable_event_watcher.h"
 
 #include "base/compiler_specific.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/win/object_watcher.h"
@@ skipping 21 matching lines @@
   watcher_.StopWatching();
 }
 
 WaitableEvent* WaitableEventWatcher::GetWatchedEvent() {
   return event_;
 }
 
 void WaitableEventWatcher::OnObjectSignaled(HANDLE h) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/418183 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION("WaitableEventWatche_OnObjectSignaled"));
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 WaitableEventWatcher::OnObjectSignaled"));
 
   WaitableEvent* event = event_;
   EventCallback callback = callback_;
   event_ = NULL;
   callback_.Reset();
   DCHECK(event);
 
   callback.Run(event);
 }
 
 }  // namespace base