Store custom properties specified in element.animate()

third_party/WebKit/Source/core/animation/EffectInput.cpp

Index: third_party/WebKit/Source/core/animation/EffectInput.cpp
diff --git a/third_party/WebKit/Source/core/animation/EffectInput.cpp b/third_party/WebKit/Source/core/animation/EffectInput.cpp
index cbfb6a3f4719e04765f46656e6116513abe1ea5b..af99d1722f7a59ccd1a7d19c8c39002e2683fbb6 100644
--- a/third_party/WebKit/Source/core/animation/EffectInput.cpp
+++ b/third_party/WebKit/Source/core/animation/EffectInput.cpp
@@ -83,7 +83,10 @@ void setKeyframeValue(Element& element, StringKeyframe& keyframe, const String&
     StyleSheetContents* styleSheetContents = element.document().elementSheet().contents();
     CSSPropertyID cssProperty = AnimationInputHelpers::keyframeAttributeToCSSProperty(property, element.document());
     if (cssProperty != CSSPropertyInvalid) {
-        keyframe.setCSSPropertyValue(cssProperty, value, styleSheetContents);
+        if (cssProperty == CSSPropertyVariable)
+            keyframe.setCSSPropertyValue(AtomicString(property), value, styleSheetContents);
+        else
+            keyframe.setCSSPropertyValue(cssProperty, value, styleSheetContents);
         return;
     }
     cssProperty = AnimationInputHelpers::keyframeAttributeToPresentationAttribute(property, element);