Implement computed style for animation shorthand and align parsing with the spec.

Source/core/css/StylePropertyShorthandCustom.cpp

Index: Source/core/css/StylePropertyShorthandCustom.cpp
diff --git a/Source/core/css/StylePropertyShorthandCustom.cpp b/Source/core/css/StylePropertyShorthandCustom.cpp
index 1e6e628c34091ae91ad949e11eaae9bf4363638b..c3d44ac9fa0a73d7bc72932d04ae66b4569fffab 100644
--- a/Source/core/css/StylePropertyShorthandCustom.cpp
+++ b/Source/core/css/StylePropertyShorthandCustom.cpp
@@ -54,6 +54,7 @@ const StylePropertyShorthand& animationShorthandForParsing()
         CSSPropertyAnimationIterationCount,
         CSSPropertyAnimationDirection,
         CSSPropertyAnimationFillMode,
+        CSSPropertyAnimationPlayState,
         CSSPropertyAnimationName
     };
     DEFINE_STATIC_LOCAL(StylePropertyShorthand, webkitAnimationLonghandsForParsing, (CSSPropertyAnimation, animationPropertiesForParsing, WTF_ARRAY_LENGTH(animationPropertiesForParsing)));
@@ -78,6 +79,7 @@ const StylePropertyShorthand& webkitAnimationShorthandForParsing()
         CSSPropertyWebkitAnimationIterationCount,
         CSSPropertyWebkitAnimationDirection,
         CSSPropertyWebkitAnimationFillMode,
+        CSSPropertyWebkitAnimationPlayState,
         CSSPropertyWebkitAnimationName
     };
     DEFINE_STATIC_LOCAL(StylePropertyShorthand, webkitAnimationLonghandsForParsing, (CSSPropertyWebkitAnimation, animationPropertiesForParsing, WTF_ARRAY_LENGTH(animationPropertiesForParsing)));