Add image-rendering: pixelated.

Source/core/css/CSSPrimitiveValueMappings.h

 /*
  * Copyright (C) 2007 Alexey Proskuryakov <ap@nypop.com>.
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 4007 matching lines @@
     switch (e) {
     case ImageRenderingAuto:
         m_value.valueID = CSSValueAuto;
         break;
     case ImageRenderingOptimizeSpeed:
         m_value.valueID = CSSValueOptimizespeed;
         break;
     case ImageRenderingOptimizeQuality:
         m_value.valueID = CSSValueOptimizequality;
         break;
+    case ImageRenderingPixelated:
+        m_value.valueID = CSSValuePixelated;
+        break;
     case ImageRenderingOptimizeContrast:
         m_value.valueID = CSSValueWebkitOptimizeContrast;
         break;
     }
 }
 
 template<> inline CSSPrimitiveValue::operator EImageRendering() const
 {
     ASSERT(isValueID());
     switch (m_value.valueID) {
     case CSSValueAuto:
         return ImageRenderingAuto;
     case CSSValueOptimizespeed:
         return ImageRenderingOptimizeSpeed;
     case CSSValueOptimizequality:
         return ImageRenderingOptimizeQuality;
+    case CSSValuePixelated:
+        return ImageRenderingPixelated;
     case CSSValueWebkitOptimizeContrast:
         return ImageRenderingOptimizeContrast;
     default:
         break;
     }
 
     ASSERT_NOT_REACHED();
     return ImageRenderingAuto;
 }
 
@@ skipping 832 matching lines @@
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return ScrollBehaviorInstant;
 }
 
 }
 
 #endif