Add image-rendering: pixelated.

Source/core/css/parser/CSSPropertyParser.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 8145 matching lines @@
         validPrimitive = (!id && validUnit(value, FNumber | FPercent, SVGAttributeMode));
         break;
 
     case CSSPropertyShapeRendering:
     // auto | optimizeSpeed | crispEdges | geometricPrecision | inherit
         if (id == CSSValueAuto || id == CSSValueOptimizespeed
             || id == CSSValueCrispedges || id == CSSValueGeometricprecision)
             validPrimitive = true;
         break;
 
-    case CSSPropertyImageRendering: // auto | optimizeSpeed |
+    case CSSPropertyImageRendering: // auto | optimizeSpeed | pixelated
+        if (RuntimeEnabledFeatures::imageRenderingPixelatedEnabled() && id == CSSValuePixelated) {
+            validPrimitive = true;
+            break;
+        }
     case CSSPropertyColorRendering: // optimizeQuality | inherit
         if (id == CSSValueAuto || id == CSSValueOptimizespeed
             || id == CSSValueOptimizequality)
             validPrimitive = true;
         break;
 
     case CSSPropertyBufferedRendering: // auto | dynamic | static
         if (id == CSSValueAuto || id == CSSValueDynamic || id == CSSValueStatic)
             validPrimitive = true;
         break;
@@ skipping 250 matching lines @@
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueFill));
     if (!seenStroke)
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueStroke));
     if (!seenMarkers)
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueMarkers));
 
     return parsedValues.release();
 }
 
 } // namespace WebCore