Collect content:attr(...)-features in RuleFeatureSet.

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 779 matching lines @@
         } else if (contentValue->isAttr()) {
             // FIXME: Can a namespace be specified for an attr(foo)?
             if (state.style()->styleType() == NOPSEUDO)
                 state.style()->setUnique();
             else
                 state.parentStyle()->setUnique();
             QualifiedName attr(nullAtom, AtomicString(contentValue->getStringValue()), nullAtom);
             const AtomicString& value = state.element()->getAttribute(attr);
             state.style()->setContent(value.isNull() ? emptyString() : value.string(), didSet);
             didSet = true;
-            // register the fact that the attribute value affects the style
-            state.contentAttrValues().append(attr.localName());
         } else if (contentValue->isCounter()) {
             Counter* counterValue = contentValue->getCounterValue();
             EListStyleType listStyleType = NoneListStyle;
             CSSValueID listStyleIdent = counterValue->listStyleIdent();
             if (listStyleIdent != CSSValueNone)
                 listStyleType = static_cast<EListStyleType>(listStyleIdent - CSSValueDisc);
             OwnPtr<CounterContent> counter = adoptPtr(new CounterContent(AtomicString(counterValue->identifier()), listStyleType, AtomicString(counterValue->separator())));
             state.style()->setContent(counter.release(), didSet);
             didSet = true;
         } else {
@@ skipping 95 matching lines @@
         return;
     case CSSValueSuper:
         svgStyle.setBaselineShift(BS_SUPER);
         return;
     default:
         ASSERT_NOT_REACHED();
     }
 }
 
 } // namespace blink