Use high precision timestamp for Event.timestamp

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 5094 matching lines @@
     // FIXME: Remove this timer once we don't need to compute layout to load plugins.
     if (!m_pluginLoadingTimer.isActive())
         m_pluginLoadingTimer.startOneShot(0, FROM_HERE);
 }
 
 void Document::pluginLoadingTimerFired(Timer<Document>*)
 {
     updateLayout();
 }
 
+double Document::monotonicTimeToZeroBasedDocumentTime(double monotonicTime) const
+{
+    if (!loader())
+        return 0;
+
+    return loader()->timing().monotonicTimeToZeroBasedDocumentTime(monotonicTime);
+}
+
 ScriptedAnimationController& Document::ensureScriptedAnimationController()
 {
     if (!m_scriptedAnimationController) {
         m_scriptedAnimationController = ScriptedAnimationController::create(this);
         // We need to make sure that we don't start up the animation controller on a background tab, for example.
         if (!page())
             m_scriptedAnimationController->suspend();
     }
     return *m_scriptedAnimationController;
 }
@@ skipping 611 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     Document::WeakDocumentSet& set = Document::liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif