remove 'widows' property because paged media support is gone so this does nothing now

sky/engine/core/animation/css/CSSAnimatableValueFactory.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 381 matching lines @@
             createFromLength(style.perspectiveOriginY(), style));
     case CSSPropertyWebkitTextStrokeColor:
         return createFromColor(property, style);
     case CSSPropertyTransform:
         return AnimatableTransform::create(style.transform());
     case CSSPropertyTransformOrigin:
         return AnimatableLengthPoint3D::create(
             createFromLength(style.transformOriginX(), style),
             createFromLength(style.transformOriginY(), style),
             createFromDouble(style.transformOriginZ()));
-    case CSSPropertyWidows:
-        return createFromDouble(style.widows());
     case CSSPropertyWidth:
         return createFromLength(style.width(), style);
     case CSSPropertyWordSpacing:
         return createFromDouble(style.wordSpacing());
     case CSSPropertyVerticalAlign:
         if (style.verticalAlign() == LENGTH)
             return createFromLength(style.verticalAlignLength(), style);
         return AnimatableUnknown::create(CSSPrimitiveValue::create(style.verticalAlign()));
     case CSSPropertyZIndex:
         return createFromDouble(style.zIndex());
     default:
         ASSERT_NOT_REACHED();
         // This return value is to avoid a release crash if possible.
         return AnimatableUnknown::create(nullptr);
     }
 }
 
 } // namespace blink