Implements CSSPropertyAPI for the transform-origin property.

third_party/WebKit/Source/core/css/CSSProperties.in

Index: third_party/WebKit/Source/core/css/CSSProperties.in
diff --git a/third_party/WebKit/Source/core/css/CSSProperties.in b/third_party/WebKit/Source/core/css/CSSProperties.in
index 6792c18cc76a5ae033cc24739b4b90e40c9e0468..ddc590440fd2b6a006baf826153022fb2d2c6ab5 100644
--- a/third_party/WebKit/Source/core/css/CSSProperties.in
+++ b/third_party/WebKit/Source/core/css/CSSProperties.in
@@ -388,7 +388,7 @@ text-underline-position runtime_flag=CSS3TextDecorations, inherited, type_name=T
 top typedom_types=[Length], keywords=[auto], supports_percentage, interpolable, initial=initialOffset, converter=convertLengthOrAuto
 touch-action converter=convertFlags<TouchAction>, type_name=TouchAction
 transform typedom_types=[Transform], keywords=[none], interpolable, converter=convertTransformOperations
-transform-origin interpolable, converter=convertTransformOrigin
+transform-origin interpolable, converter=convertTransformOrigin, api_class
 transform-style name_for_methods=TransformStyle3D
 translate runtime_flag=CSSIndependentTransformProperties, converter=convertTranslate, interpolable, api_class
 rotate runtime_flag=CSSIndependentTransformProperties, converter=convertRotate, interpolable