Allow assertions to be enabled in Blink Release builds.

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 2613 matching lines @@
         if (isValueConflictingWithCurrentEdge(ident1, secondPositionKeyword))
             return;
 
         value1 = createPrimitiveValuePair(parsedValue1, firstPositionValue);
         value2 = createPrimitiveValuePair(cssValuePool().createIdentifierValue(secondPositionKeyword), secondPositionValue);
     }
 
     if (ident1 == CSSValueTop || ident1 == CSSValueBottom || swapNeeded)
         value1.swap(value2);
 
-#ifndef NDEBUG
+#if ENABLE(ASSERT)
     CSSPrimitiveValue* first = toCSSPrimitiveValue(value1.get());
     CSSPrimitiveValue* second = toCSSPrimitiveValue(value2.get());
     ident1 = first->getPairValue()->first()->getValueID();
     ident2 = second->getPairValue()->first()->getValueID();
     ASSERT(ident1 == CSSValueLeft || ident1 == CSSValueRight);
     ASSERT(ident2 == CSSValueBottom || ident2 == CSSValueTop);
 #endif
 }
 
 inline bool CSSPropertyParser::isPotentialPositionValue(CSSParserValue* value)
@@ skipping 5858 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