Prevent will-change:transform from changing the computed value of transform

Source/core/style/ComputedStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * 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.
  *
@@ skipping 879 matching lines @@
         case CSSPropertyBottom:
         case CSSPropertyRight:
             return true;
         default:
             break;
         }
     }
     return false;
 }
 
+bool ComputedStyle::hasWillChangeTransformHint() const
+{
+    for (const auto& property: rareNonInheritedData->m_willChange->m_properties) {
+        switch (property) {
+        case CSSPropertyTransform:
+        case CSSPropertyAliasWebkitTransform:
+            return true;
+        default:
+            break;
+        }
+    }
+    return false;
+}
+
 bool ComputedStyle::requireTransformOrigin(ApplyTransformOrigin applyOrigin, ApplyMotionPath applyMotionPath) const
 {
     const Vector<RefPtr<TransformOperation>>& transformOperations = transform().operations();
 
     // transform-origin brackets the transform with translate operations.
     // Optimize for the case where the only transform is a translation, since the transform-origin is irrelevant
     // in that case.
     if (applyOrigin != IncludeTransformOrigin)
         return false;
 
@@ skipping 875 matching lines @@
 }
 
 void ComputedStyle::copyChildDependentFlagsFrom(const ComputedStyle& other)
 {
     setEmptyState(other.emptyState());
     if (other.hasExplicitlyInheritedProperties())
         setHasExplicitlyInheritedProperties();
 }
 
 } // namespace blink