Web Animations: Zero time of the document timeline should correspond with navigationStart

Source/core/animation/AnimationTimeline.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/animation/AnimationTimeline.h"
 
 #include "core/animation/ActiveAnimations.h"
 #include "core/animation/AnimationClock.h"
 #include "core/dom/Document.h"
 #include "core/frame/FrameView.h"
+#include "core/loader/DocumentLoader.h"
 #include "core/page/Page.h"
 #include "platform/TraceEvent.h"
 
 namespace blink {
 
 namespace {
 
 bool compareAnimationPlayers(const RefPtrWillBeMember<blink::AnimationPlayer>& left, const RefPtrWillBeMember<blink::AnimationPlayer>& right)
 {
     return AnimationPlayer::hasLowerPriority(left.get(), right.get());
 }
 
 }
 
 // This value represents 1 frame at 30Hz plus a little bit of wiggle room.
 // TODO: Plumb a nominal framerate through and derive this value from that.
 const double AnimationTimeline::s_minimumDelay = 0.04;
 
 
 PassRefPtrWillBeRawPtr<AnimationTimeline> AnimationTimeline::create(Document* document, PassOwnPtrWillBeRawPtr<PlatformTiming> timing)
 {
     return adoptRefWillBeNoop(new AnimationTimeline(document, timing));
 }
 
 AnimationTimeline::AnimationTimeline(Document* document, PassOwnPtrWillBeRawPtr<PlatformTiming> timing)
     : m_document(document)
+    , m_zeroTime(0)
 {
     if (!timing)
         m_timing = adoptPtrWillBeNoop(new AnimationTimelineTiming(this));
     else
         m_timing = timing;
 
     ASSERT(document);
 }
 
 AnimationTimeline::~AnimationTimeline()
@@ skipping 84 matching lines @@
     if (m_timeline->m_document && m_timeline->m_document->view())
         m_timeline->m_document->view()->scheduleAnimation();
 }
 
 void AnimationTimeline::AnimationTimelineTiming::trace(Visitor* visitor)
 {
     visitor->trace(m_timeline);
     AnimationTimeline::PlatformTiming::trace(visitor);
 }
 
+double AnimationTimeline::zeroTime()
+{
+    if (!m_zeroTime && m_document && m_document->loader()) {
+        m_zeroTime = m_document->loader()->timing()->referenceMonotonicTime();
+    }
+    return m_zeroTime;
+}
+
 double AnimationTimeline::currentTime(bool& isNull)
 {
     return currentTimeInternal(isNull) * 1000;
 }
 
 double AnimationTimeline::currentTimeInternal(bool& isNull)
 {
     if (!m_document) {
         isNull = true;
         return std::numeric_limits<double>::quiet_NaN();
@@ skipping 56 matching lines @@
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_document);
     visitor->trace(m_timing);
     visitor->trace(m_playersNeedingUpdate);
     visitor->trace(m_players);
 #endif
 }
 
 } // namespace