Remove webkit-margin-collapse

sky/engine/core/css/CSSProperties.in

 // This file specifies all the CSS properties we support and the necessary
 // information for our code generation. The various supported arguments
 // are described below with example usage
 
 
 // - alias_for=other-property
 // Properties specifying alias_for do not get their own enum and instead map
 // directly onto the CSSPropertyID they alias. Currently this means that the
 // UseCounter will not pick up on these (crbug.com/304855)
 
@@ skipping 221 matching lines @@
 -webkit-border-image initial=initialNinePieceImage, custom_value
 -webkit-border-vertical-spacing animatable, inherited, name_for_methods=VerticalBorderSpacing, converter=convertComputedLength<short>
 -webkit-box-decoration-break
 -webkit-box-shadow animatable, use_handlers_for=CSSPropertyBoxShadow
 -webkit-clip-path animatable, custom_value
 -webkit-filter animatable, custom_value
 -webkit-highlight inherited, converter=convertString<CSSValueNone>
 -webkit-hyphenate-character inherited, name_for_methods=HyphenationString, converter=convertString<CSSValueAuto>
 -webkit-line-box-contain inherited, converter=convertLineBoxContain
 -webkit-line-break inherited, type_name=LineBreak
--webkit-margin-after-collapse type_name=EMarginCollapse
--webkit-margin-before-collapse type_name=EMarginCollapse
--webkit-margin-bottom-collapse type_name=EMarginCollapse, name_for_methods=MarginAfterCollapse
--webkit-margin-top-collapse type_name=EMarginCollapse, name_for_methods=MarginBeforeCollapse
 -webkit-mask-box-image-outset animatable, custom_all
 -webkit-mask-box-image-repeat custom_all
 -webkit-mask-box-image-slice animatable, custom_all
 -webkit-mask-box-image-source animatable, custom_value
 -webkit-mask-box-image-width animatable, custom_all
 -webkit-mask-clip custom_all
 -webkit-mask-composite custom_all
 -webkit-mask-image animatable, custom_all
 -webkit-mask-origin custom_all
 -webkit-mask-position-x animatable, custom_all
@@ skipping 114 matching lines @@
 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-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
 // "-webkit-border-radius: 1px 2px" behaves as "border-radius: 1px / 2px"
 -webkit-border-radius longhands=border-top-left-radius;border-top-right-radius;border-bottom-right-radius;border-bottom-left-radius
 -webkit-border-start longhands=-webkit-border-start-width;-webkit-border-start-style;-webkit-border-start-color
--webkit-margin-collapse longhands=-webkit-margin-before-collapse;-webkit-margin-after-collapse
 -webkit-mask longhands=-webkit-mask-image;-webkit-mask-position-x;-webkit-mask-position-y;-webkit-mask-size;-webkit-mask-repeat-x;-webkit-mask-repeat-y;-webkit-mask-origin;-webkit-mask-clip
 -webkit-mask-box-image longhands=-webkit-mask-box-image-source;-webkit-mask-box-image-slice;-webkit-mask-box-image-width;-webkit-mask-box-image-outset;-webkit-mask-box-image-repeat
 -webkit-mask-position longhands=-webkit-mask-position-x;-webkit-mask-position-y
 -webkit-mask-repeat longhands=-webkit-mask-repeat-x;-webkit-mask-repeat-y
 -webkit-text-emphasis longhands=-webkit-text-emphasis-style;-webkit-text-emphasis-color
 -webkit-text-stroke longhands=-webkit-text-stroke-width;-webkit-text-stroke-color
 -webkit-transform-origin longhands=-webkit-transform-origin-x;-webkit-transform-origin-y;-webkit-transform-origin-z
 -webkit-transition longhands=-webkit-transition-property;-webkit-transition-duration;-webkit-transition-timing-function;-webkit-transition-delay
 
 // Aliases; these map to the same CSSPropertyID
@@ skipping 15 matching lines @@
 -webkit-flex alias_for=flex
 -webkit-flex-basis alias_for=flex-basis
 -webkit-flex-direction alias_for=flex-direction
 -webkit-flex-flow alias_for=flex-flow
 -webkit-flex-grow alias_for=flex-grow
 -webkit-flex-shrink alias_for=flex-shrink
 -webkit-flex-wrap alias_for=flex-wrap
 -webkit-justify-content alias_for=justify-content
 -webkit-opacity alias_for=opacity
 -webkit-order alias_for=order