[wip] simplify -webkit-appearance adjust step

Source/core/core.gypi

 {
     'includes': [
       'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/Animation.idl',
             'animation/AnimationEffect.idl',
             'animation/AnimationPlayer.idl',
@@ skipping 1713 matching lines @@
             'rendering/shapes/RectangleShape.h',
             'rendering/shapes/Shape.cpp',
             'rendering/shapes/Shape.h',
             'rendering/shapes/ShapeInterval.h',
             'rendering/shapes/ShapeOutsideInfo.cpp',
             'rendering/shapes/ShapeOutsideInfo.h',
             'rendering/style/AppliedTextDecoration.cpp',
             'rendering/style/BasicShapes.cpp',
             'rendering/style/BorderImageLength.h',
             'rendering/style/BorderImageLengthBox.h',
-            'rendering/style/CachedUAStyle.h',
             'rendering/style/ContentData.cpp',
             'rendering/style/CounterDirectives.cpp',
             'rendering/style/FillLayer.cpp',
             'rendering/style/GridCoordinate.h',
             'rendering/style/GridResolvedPosition.cpp',
             'rendering/style/GridResolvedPosition.h',
             'rendering/style/KeyframeList.cpp',
             'rendering/style/KeyframeList.h',
             'rendering/style/NinePieceImage.cpp',
             'rendering/style/QuotesData.cpp',
@@ skipping 1678 matching lines @@
             'rendering/RenderOverflowTest.cpp',
             'rendering/RenderTableCellTest.cpp',
             'rendering/RenderTableRowTest.cpp',
             'rendering/shapes/BoxShapeTest.cpp',
             'testing/UnitTestHelpers.cpp',
             'testing/UnitTestHelpers.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }