Extend PropertyHandle to include custom property identifiers

third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp

Index: third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
diff --git a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
index 9de013e0504219538784dd11a15444359931adb5..e04f302c55f7bf922fbd4d270303e4f7188e16da 100644
--- a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
+++ b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
@@ -125,7 +125,7 @@ static StringKeyframeEffectModel* createKeyframeEffectModel(StyleResolver* resol
     for (size_t i = 1; i < keyframes.size(); i++) {
         if (keyframes[i]->offset() == keyframes[targetIndex]->offset()) {
             for (const auto& property : keyframes[i]->properties())
-                keyframes[targetIndex]->setCSSPropertyValue(property.cssProperty(), keyframes[i]->cssPropertyValue(property.cssProperty()));
+                keyframes[targetIndex]->setCSSPropertyValue(property.cssProperty(), keyframes[i]->cssPropertyValue(property));
         } else {
             targetIndex++;
             keyframes[targetIndex] = keyframes[i];