Clear started transitions overwritten by duration 0 transitions on the same property

third_party/WebKit/Source/core/animation/css/CSSAnimationUpdate.h

 // Copyright 2015 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.
 
 #ifndef CSSAnimationUpdate_h
 #define CSSAnimationUpdate_h
 
 #include "core/animation/EffectStack.h"
 #include "core/animation/InertEffect.h"
 #include "core/animation/Interpolation.h"
@@ skipping 159 matching lines @@
                        const InertEffect& effect) {
     NewTransition newTransition;
     newTransition.id = id;
     newTransition.from = std::move(from);
     newTransition.to = std::move(to);
     newTransition.reversingAdjustedStartValue = reversingAdjustedStartValue;
     newTransition.reversingShorteningFactor = reversingShorteningFactor;
     newTransition.effect = &effect;
     m_newTransitions.set(id, newTransition);
   }
+  void unstartTransition(CSSPropertyID id) { m_newTransitions.remove(id); }
   bool isCancelledTransition(CSSPropertyID id) const {
     return m_cancelledTransitions.contains(id);
   }
   void cancelTransition(CSSPropertyID id) { m_cancelledTransitions.insert(id); }
   void finishTransition(CSSPropertyID id) { m_finishedTransitions.insert(id); }
 
   const HeapVector<NewCSSAnimation>& newAnimations() const {
     return m_newAnimations;
   }
   const Vector<size_t>& cancelledAnimationIndices() const {
@@ skipping 89 matching lines @@
 
   ActiveInterpolationsMap m_activeInterpolationsForAnimations;
   ActiveInterpolationsMap m_activeInterpolationsForTransitions;
 
   friend class PendingAnimationUpdate;
 };
 
 }  // namespace blink
 
 #endif