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

Source/core/css/CSSShorthands.in

Index: Source/core/css/CSSShorthands.in
diff --git a/Source/core/css/CSSShorthands.in b/Source/core/css/CSSShorthands.in
index 9738a793d4d89a2d88be5b6f372534898630ffc8..c98df406353dacf94d91420a20bbf277e4e57198 100644
--- a/Source/core/css/CSSShorthands.in
+++ b/Source/core/css/CSSShorthands.in
@@ -3,7 +3,7 @@
 // followed by the longhands associated to the shorthand.
 // Note: Mandatory blank line to skip parameter parsing phase
 
-animation longhands=animation-name;animation-duration;animation-timing-function;animation-delay;animation-iteration-count;animation-direction;animation-fill-mode, runtimeEnabledShorthand=CSSAnimationUnprefixed
+animation longhands=animation-name;animation-duration;animation-timing-function;animation-delay;animation-iteration-count;animation-direction;animation-fill-mode;animation-play-state, runtimeEnabledShorthand=CSSAnimationUnprefixed
 background longhands=background-image;background-position-x;background-position-y;background-size;background-repeat-x;background-repeat-y;background-attachment;background-origin;background-clip;background-color
 background-position longhands=background-position-x;background-position-y
 background-repeat longhands=background-repeat-x;background-repeat-y
@@ -32,7 +32,7 @@ outline longhands=outline-color;outline-style;outline-width
 overflow longhands=overflow-x;overflow-y
 padding longhands=padding-top;padding-right;padding-bottom;padding-left
 transition longhands=transition-property;transition-duration;transition-timing-function;transition-delay
--webkit-animation longhands=-webkit-animation-name;-webkit-animation-duration;-webkit-animation-timing-function;-webkit-animation-delay;-webkit-animation-iteration-count;-webkit-animation-direction;-webkit-animation-fill-mode
+-webkit-animation longhands=-webkit-animation-name;-webkit-animation-duration;-webkit-animation-timing-function;-webkit-animation-delay;-webkit-animation-iteration-count;-webkit-animation-direction;-webkit-animation-fill-mode;-webkit-animation-play-state
 -webkit-border-after longhands=-webkit-border-after-width;-webkit-border-after-style;-webkit-border-after-color
 -webkit-border-before longhands=-webkit-border-before-width;-webkit-border-before-style;-webkit-border-before-color
 -webkit-border-end longhands=-webkit-border-end-width;-webkit-border-end-style;-webkit-border-end-color