Use alias_for with trivial property aliases

Source/core/animation/css/CSSPropertyEquality.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/animation/css/CSSPropertyEquality.h"
 
 #include "core/animation/css/CSSAnimations.h"
 #include "core/style/DataEquivalency.h"
 #include "core/style/ComputedStyle.h"
@@ skipping 234 matching lines @@
         return a.verticalAlign() == b.verticalAlign()
             && (a.verticalAlign() != LENGTH || a.verticalAlignLength() == b.verticalAlignLength());
     case CSSPropertyVisibility:
         return a.visibility() == b.visibility();
     case CSSPropertyWebkitBackgroundSize:
         return fillLayersEqual<CSSPropertyWebkitBackgroundSize>(a.backgroundLayers(), b.backgroundLayers());
     case CSSPropertyWebkitBorderHorizontalSpacing:
         return a.horizontalBorderSpacing() == b.horizontalBorderSpacing();
     case CSSPropertyWebkitBorderVerticalSpacing:
         return a.verticalBorderSpacing() == b.verticalBorderSpacing();
-    case CSSPropertyWebkitBoxShadow:
-        return dataEquivalent(a.boxShadow(), b.boxShadow());
     case CSSPropertyWebkitClipPath:
         return dataEquivalent(a.clipPath(), b.clipPath());
     case CSSPropertyWebkitColumnCount:
         return a.columnCount() == b.columnCount();
     case CSSPropertyWebkitColumnGap:
         return a.columnGap() == b.columnGap();
     case CSSPropertyWebkitColumnRuleColor:
         return a.columnRuleColor() == b.columnRuleColor()
             && a.visitedLinkColumnRuleColor() == b.visitedLinkColumnRuleColor();
     case CSSPropertyWebkitColumnRuleWidth:
@@ skipping 61 matching lines @@
         return a.svgStyle().ry() == b.svgStyle().ry();
     case CSSPropertyZIndex:
         return a.zIndex() == b.zIndex();
     default:
         ASSERT_NOT_REACHED();
         return true;
     }
 }
 
 }