Don't animate a progress bar if it isn't animated

third_party/WebKit/Source/core/layout/LayoutProgress.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 56 matching lines @@
 {
     return m_animating ? (fmod((currentTime() - m_animationStartTime), m_animationDuration) / m_animationDuration) : 0;
 }
 
 bool LayoutProgress::isDeterminate() const
 {
     return (HTMLProgressElement::IndeterminatePosition != position()
         && HTMLProgressElement::InvalidPosition != position());
 }
 
+bool LayoutProgress::isAnimationTimerActive() const
+{
+    return m_animationTimer.isActive();

[Xianzhu, 2016/02/22 23:17:27]

Nit: Can you use m_animating (and rename this function to isAnimating())?

[Stephen Chennney, 2016/02/23 19:24:01]

I would rather check the timer itself, as that will catch bugs with both
m_animating being set and the timer being set (because the timer can only be
right is m_animating is right).

Better yet is to check both the flag and the timer, which will test that the
code keeps them correctly in sync.

+}
+
 void LayoutProgress::animationTimerFired(Timer<LayoutProgress>*)
 {
     setShouldDoFullPaintInvalidation();
     if (!m_animationTimer.isActive() && m_animating)
         m_animationTimer.startOneShot(m_animationRepeatInterval, BLINK_FROM_HERE);
 }
 
 void LayoutProgress::updateAnimationState()
 {
     m_animationDuration = LayoutTheme::theme().animationDurationForProgressBar();
     m_animationRepeatInterval = LayoutTheme::theme().animationRepeatIntervalForProgressBar();
 
-    bool animating = style()->hasAppearance() && m_animationDuration > 0;
+    bool animating = !isDeterminate() && style()->hasAppearance() && m_animationDuration > 0;
     if (animating == m_animating)
         return;
 
     m_animating = animating;
     if (m_animating) {
         m_animationStartTime = currentTime();
         m_animationTimer.startOneShot(m_animationRepeatInterval, BLINK_FROM_HERE);
     } else {
         m_animationTimer.stop();
     }
 }
 
 HTMLProgressElement* LayoutProgress::progressElement() const
 {
     if (!node())
         return nullptr;
 
     if (isHTMLProgressElement(*node()))
         return toHTMLProgressElement(node());
 
     ASSERT(node()->shadowHost());
     return toHTMLProgressElement(node()->shadowHost());
 }
 
 } // namespace blink