Reset animation state when animation policy is changed.

Source/platform/graphics/BitmapImage.cpp

 /*
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple 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 425 matching lines @@
         m_repetitionCount = m_source.repetitionCount();
         m_repetitionCountStatus = (imageKnownToBeComplete || m_repetitionCount == cAnimationNone) ? Certain : Uncertain;
     }
     return m_repetitionCount;
 }
 
 bool BitmapImage::shouldAnimate()
 {
     bool animated = repetitionCount(false) != cAnimationNone && !m_animationFinished && imageObserver();
     if (imageObserver()) {
+        ImageAnimationPolicy oldPolicy = m_animationPolicy;
         imageObserver()->imageAnimationPolicy(this, m_animationPolicy);
+        if (oldPolicy != m_animationPolicy)
+            resetAnimation();
         if (animated && m_animationPolicy == ImageAnimationPolicyNoAnimation)
             animated = false;
     }
     return animated;
 }
 
 void BitmapImage::startAnimation(CatchUpAnimation catchUpIfNecessary)
 {
     if (m_frameTimer || !shouldAnimate() || frameCount() <= 1)
         return;
@@ skipping 196 matching lines @@
 
     return m_isSolidColor && !m_currentFrame;
 }
 
 Color BitmapImage::solidColor() const
 {
     return m_solidColor;
 }
 
 } // namespace blink