Multiple selectors setting relative font-weight names to an element result in a cumulative result

Source/core/css/resolver/StyleBuilderCustom.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
@@ skipping 267 matching lines @@
 void StyleBuilderFunctions::applyValueCSSPropertyFontWeight(StyleResolverState& state, CSSValue* value)
 {
     if (!value->isPrimitiveValue())
         return;
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     switch (primitiveValue->getValueID()) {
     case CSSValueInvalid:
         ASSERT_NOT_REACHED();
         break;
     case CSSValueBolder:
+        state.fontBuilder().setWeight(state.parentStyle()->fontDescription().weight());
         state.fontBuilder().setWeightBolder();
         break;
     case CSSValueLighter:
+        state.fontBuilder().setWeight(state.parentStyle()->fontDescription().weight());
         state.fontBuilder().setWeightLighter();
         break;
     default:
         state.fontBuilder().setWeight(*primitiveValue);
     }
 }
 
 void StyleBuilderFunctions::applyValueCSSPropertyLineHeight(StyleResolverState& state, CSSValue* value)
 {
     if (!value->isPrimitiveValue())
@@ skipping 1909 matching lines @@
         break;
     }
     case CSSPropertyEnableBackground:
         // Silently ignoring this property for now
         // http://bugs.webkit.org/show_bug.cgi?id=6022
         break;
     }
 }
 
 } // namespace WebCore