Expose the CSS background-blend-mode property,

Source/core/css/parser/BisonCSSParser-in.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 4084 matching lines @@
                     break;
                 }
                 case CSSPropertyWebkitBackgroundComposite:
                 case CSSPropertyWebkitMaskComposite:
                     if (val->id >= CSSValueClear && val->id <= CSSValuePlusLighter) {
                         currValue = cssValuePool().createIdentifierValue(val->id);
                         m_valueList->next();
                     }
                     break;
                 case CSSPropertyBackgroundBlendMode:
-                    if (RuntimeEnabledFeatures::cssCompositingEnabled() && (val->id == CSSValueNormal || val->id == CSSValueMultiply
+                    if (val->id == CSSValueNormal || val->id == CSSValueMultiply
                         || val->id == CSSValueScreen || val->id == CSSValueOverlay || val->id == CSSValueDarken
                         || val->id == CSSValueLighten ||  val->id == CSSValueColorDodge || val->id == CSSValueColorBurn
                         || val->id == CSSValueHardLight || val->id == CSSValueSoftLight || val->id == CSSValueDifference
                         || val->id == CSSValueExclusion || val->id == CSSValueHue || val->id == CSSValueSaturation
-                        || val->id == CSSValueColor || val->id == CSSValueLuminosity)) {
+                        || val->id == CSSValueColor || val->id == CSSValueLuminosity) {
                         currValue = cssValuePool().createIdentifierValue(val->id);
                         m_valueList->next();
                     }
                     break;
                 case CSSPropertyBackgroundRepeat:
                 case CSSPropertyWebkitMaskRepeat:
                     parseFillRepeat(currValue, currValue2);
                     // parseFillRepeat advances the m_valueList pointer
                     break;
                 case CSSPropertyBackgroundSize:
@@ skipping 6040 matching lines @@
 {
     // The tokenizer checks for the construct of an+b.
     // However, since the {ident} rule precedes the {nth} rule, some of those
     // tokens are identified as string literal. Furthermore we need to accept
     // "odd" and "even" which does not match to an+b.
     return equalIgnoringCase(token, "odd") || equalIgnoringCase(token, "even")
         || equalIgnoringCase(token, "n") || equalIgnoringCase(token, "-n");
 }
 
 }