Trace where timers were scheduled in Blink

Source/platform/Timer.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 185 matching lines @@
 #endif
 {
 }
 
 TimerBase::~TimerBase()
 {
     stop();
     ASSERT(!inHeap());
 }
 
-void TimerBase::start(double nextFireInterval, double repeatInterval)
+void TimerBase::start(double nextFireInterval, double repeatInterval, const TraceLocation& caller)
 {
     ASSERT(m_thread == currentThread());
 
+    m_location = caller;
     m_repeatInterval = repeatInterval;
     setNextFireTime(monotonicallyIncreasingTime() + nextFireInterval);
 }
 
 void TimerBase::stop()
 {
     ASSERT(m_thread == currentThread());
 
     m_repeatInterval = 0;
     setNextFireTime(0);
@@ skipping 186 matching lines @@
 }
 
 double TimerBase::nextUnalignedFireInterval() const
 {
     ASSERT(isActive());
     return max(m_unalignedNextFireTime - monotonicallyIncreasingTime(), 0.0);
 }
 
 } // namespace WebCore