Remove the CSSOM.

sky/engine/core/core.gni

Index: sky/engine/core/core.gni
diff --git a/sky/engine/core/core.gni b/sky/engine/core/core.gni
index ef64f1855ec8f1e1756fe729effb6adb3ce19896..d309688f472d6d73b5c74b0e17cdcd3a32820473 100644
--- a/sky/engine/core/core.gni
+++ b/sky/engine/core/core.gni
@@ -138,14 +138,10 @@ sky_core_files = [
   "css/CSSCursorImageValue.cpp",
   "css/CSSCursorImageValue.h",
   "css/CSSCustomFontData.h",
-  "css/CSSFilterRule.cpp",
-  "css/CSSFilterRule.h",
   "css/CSSFilterValue.cpp",
   "css/CSSFilterValue.h",
   "css/CSSFontFace.cpp",
   "css/CSSFontFace.h",
-  "css/CSSFontFaceRule.cpp",
-  "css/CSSFontFaceRule.h",
   "css/CSSFontFaceSource.cpp",
   "css/CSSFontFaceSource.h",
   "css/CSSFontFaceSrcValue.cpp",
@@ -161,8 +157,6 @@ sky_core_files = [
   "css/CSSFunctionValue.h",
   "css/CSSGradientValue.cpp",
   "css/CSSGradientValue.h",
-  "css/CSSGroupingRule.cpp",
-  "css/CSSGroupingRule.h",
   "css/CSSHelper.h",
   "css/CSSImageGeneratorValue.cpp",
   "css/CSSImageGeneratorValue.h",
@@ -174,18 +168,12 @@ sky_core_files = [
   "css/CSSInheritedValue.h",
   "css/CSSInitialValue.cpp",
   "css/CSSInitialValue.h",
-  "css/CSSKeyframeRule.cpp",
-  "css/CSSKeyframeRule.h",
-  "css/CSSKeyframesRule.cpp",
-  "css/CSSKeyframesRule.h",
   "css/CSSLineBoxContainValue.cpp",
   "css/CSSLineBoxContainValue.h",
   "css/CSSMarkup.cpp",
   "css/CSSMarkup.h",
   "css/CSSMatrix.cpp",
   "css/CSSMatrix.h",
-  "css/CSSMediaRule.cpp",
-  "css/CSSMediaRule.h",
   "css/CSSOMUtils.cpp",
   "css/CSSOMUtils.h",
   "css/CSSPrimitiveValue.cpp",
@@ -196,10 +184,6 @@ sky_core_files = [
   "css/CSSPropertyMetadata.h",
   "css/CSSPropertySourceData.cpp",
   "css/CSSPropertySourceData.h",
-  "css/CSSRule.cpp",
-  "css/CSSRule.h",
-  "css/CSSRuleList.cpp",
-  "css/CSSRuleList.h",
   "css/CSSSegmentedFontFace.cpp",
   "css/CSSSegmentedFontFace.h",
   "css/CSSSelector.cpp",
@@ -209,12 +193,8 @@ sky_core_files = [
   "css/CSSShadowValue.cpp",
   "css/CSSShadowValue.h",
   "css/CSSStyleDeclaration.h",
-  "css/CSSStyleRule.cpp",
-  "css/CSSStyleRule.h",
   "css/CSSStyleSheet.cpp",
   "css/CSSStyleSheet.h",
-  "css/CSSSupportsRule.cpp",
-  "css/CSSSupportsRule.h",
   "css/CSSTimingFunctionValue.cpp",
   "css/CSSTimingFunctionValue.h",
   "css/CSSToLengthConversionData.cpp",
@@ -223,7 +203,6 @@ sky_core_files = [
   "css/CSSTransformValue.h",
   "css/CSSUnicodeRangeValue.cpp",
   "css/CSSUnicodeRangeValue.h",
-  "css/CSSUnknownRule.h",
   "css/CSSValue.cpp",
   "css/CSSValue.h",
   "css/CSSValueList.cpp",
@@ -359,12 +338,16 @@ sky_core_files = [
   "css/StylePropertyShorthandCustom.cpp",
   "css/StyleRule.cpp",
   "css/StyleRule.h",
+  "css/StyleKeyframe.h",
+  "css/StyleKeyframe.cpp",
+  "css/StyleRuleKeyframes.h",
+  "css/StyleRuleKeyframes.cpp",
   "css/StyleSheet.cpp",
   "css/StyleSheet.h",
-  "css/StyleSheetContents.cpp",
-  "css/StyleSheetContents.h",
   "css/StyleSheetList.cpp",
   "css/StyleSheetList.h",
+  "css/StyleSheetContents.cpp",
+  "css/StyleSheetContents.h",
   "dom/ActiveDOMObject.cpp",
   "dom/ActiveDOMObject.h",
   "dom/Attr.cpp",
@@ -1296,36 +1279,22 @@ core_idl_files = get_path_info([
   "app/Application.idl",
   "app/Module.idl",
   "css/CSS.idl",
-  "css/CSSFilterRule.idl",
   "css/CSSFilterValue.idl",
-  "css/CSSFontFaceRule.idl",
-  "css/CSSKeyframeRule.idl",
-  "css/CSSKeyframesRule.idl",
   "css/CSSMatrix.idl",
-  "css/CSSMediaRule.idl",
   "css/CSSPrimitiveValue.idl",
-  "css/CSSRule.idl",
-  "css/CSSRuleList.idl",
   "css/CSSStyleDeclaration.idl",
-  "css/CSSStyleRule.idl",
-  "css/CSSStyleSheet.idl",
-  "css/CSSSupportsRule.idl",
   "css/CSSTransformValue.idl",
-  "css/CSSUnknownRule.idl",
   "css/CSSValue.idl",
   "css/CSSValueList.idl",
   "css/FontFace.idl",
   "css/FontFaceSet.idl",
   "css/FontFaceSetForEachCallback.idl",
   "css/FontFaceSetLoadEvent.idl",
-  "css/MediaList.idl",
   "css/MediaQueryList.idl",
   "css/MediaQueryListEvent.idl",
   "css/Rect.idl",
   "css/RGBColor.idl",
   "css/StyleMedia.idl",
-  "css/StyleSheet.idl",
-  "css/StyleSheetList.idl",
   "dom/Attr.idl",
   "dom/CharacterData.idl",
   "dom/ClientRect.idl",