No need to store invalid media queries.

Source/core/css/MediaQueryEvaluator.cpp

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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 113 matching lines @@
 
     const Vector<OwnPtr<MediaQuery> >& queries = querySet->queryVector();
     if (!queries.size())
         return true; // empty query list evaluates to true
 
     // iterate over queries, stop if any of them eval to true (OR semantics)
     bool result = false;
     for (size_t i = 0; i < queries.size() && !result; ++i) {
         MediaQuery* query = queries[i].get();
 
-        if (query->ignored())
-            continue;
-
         if (mediaTypeMatch(query->mediaType())) {
             const Vector<OwnPtr<MediaQueryExp> >* exps = query->expressions();
             // iterate through expressions, stop if any of them eval to false
             // (AND semantics)
             size_t j = 0;
             for (; j < exps->size(); ++j) {
                 bool exprResult = eval(exps->at(j).get());
                 if (styleResolver && exps->at(j)->isViewportDependent())
                     styleResolver->addViewportDependentMediaQueryResult(exps->at(j).get(), exprResult);
                 if (!exprResult)
@@ skipping 527 matching lines @@
     gFunctionMap->set(name##MediaFeature.impl(), name##MediaFeatureEval);
     CSS_MEDIAQUERY_NAMES_FOR_EACH_MEDIAFEATURE(ADD_TO_FUNCTIONMAP);
 #undef ADD_TO_FUNCTIONMAP
 }
 
 bool MediaQueryEvaluator::eval(const MediaQueryExp* expr) const
 {
     if (!m_frame || !m_style)
         return m_expResult;
 
-    if (!expr->isValid())
-        return false;
-
     if (!gFunctionMap)
         createFunctionMap();
 
     // call the media feature evaluation function. Assume no prefix
     // and let trampoline functions override the prefix if prefix is
     // used
     EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
     if (func)
         return func(expr->value(), m_style.get(), m_frame, NoPrefix);
 
     return false;
 }
 
 } // namespace