Trace where timers were scheduled in Blink

Source/modules/screen_orientation/ScreenOrientation.cpp

 // Copyright 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 "config.h"
 #include "modules/screen_orientation/ScreenOrientation.h"
 
 #include "core/frame/DOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Screen.h"
@@ skipping 65 matching lines @@
     , m_lockedOrientations(WebScreenOrientationDefault)
 {
 }
 
 void ScreenOrientation::lockOrientationAsync(blink::WebScreenOrientations orientations)
 {
     if (m_lockedOrientations == orientations)
         return;
     m_lockedOrientations = orientations;
     if (!m_orientationLockTimer.isActive())
-        m_orientationLockTimer.startOneShot(0);
+        m_orientationLockTimer.startOneShot(0, FROM_HERE);
 }
 
 void ScreenOrientation::orientationLockTimerFired(Timer<ScreenOrientation>*)
 {
     if (m_lockedOrientations == WebScreenOrientationDefault)
         blink::Platform::current()->unlockOrientation();
     else
         blink::Platform::current()->lockOrientation(m_lockedOrientations);
 }
 
@@ skipping 56 matching lines @@
     ScreenOrientation::from(screen).lockOrientationAsync(orientations);
     return true;
 }
 
 void ScreenOrientation::unlockOrientation(Screen& screen)
 {
     ScreenOrientation::from(screen).lockOrientationAsync(WebScreenOrientationDefault);
 }
 
 } // namespace WebCore