Fix MQEvaluator::mediaType() related perf regressions.

Source/core/css/resolver/StyleResolver.cpp

 /*
  * 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.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 13 matching lines @@
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/css/resolver/StyleResolver.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/HTMLNames.h"
+#include "core/MediaTypeNames.h"
 #include "core/StylePropertyShorthand.h"
 #include "core/animation/ActiveAnimations.h"
 #include "core/animation/Animation.h"
 #include "core/animation/AnimationTimeline.h"
 #include "core/animation/StyleInterpolation.h"
 #include "core/animation/animatable/AnimatableValue.h"
 #include "core/animation/css/CSSAnimatableValueFactory.h"
 #include "core/animation/css/CSSAnimations.h"
 #include "core/css/CSSCalculationValue.h"
 #include "core/css/CSSDefaultStyleSheets.h"
@@ skipping 416 matching lines @@
     collector.clearMatchedRules();
     collector.matchedResult().ranges.lastUserRule = collector.matchedResult().matchedProperties.size() - 1;
 
     MatchRequest matchRequest(m_watchedSelectorsRules.get());
     RuleRange ruleRange = collector.matchedResult().ranges.userRuleRange();
     collector.collectMatchingRules(matchRequest, ruleRange);
 
     collector.sortAndTransferMatchedRules();
 }
 
+static bool printMediaType(FrameView* view)
+{
+    if (!view)
+        return false;
+    return equalIgnoringCase(view->mediaType(), MediaTypeNames::print);
+}
+
 void StyleResolver::matchUARules(ElementRuleCollector& collector)
 {
     collector.setMatchingUARules(true);
 
     CSSDefaultStyleSheets& defaultStyleSheets = CSSDefaultStyleSheets::instance();
-    RuleSet* userAgentStyleSheet = m_medium->mediaTypeMatchSpecific("print")
+    RuleSet* userAgentStyleSheet = printMediaType(document().view())

[esprehn, 2014/07/25 23:42:04]

Why would this be slow? mediaTypeMatchSpecific just compares the string right?

         ? defaultStyleSheets.defaultPrintStyle() : defaultStyleSheets.defaultStyle();
     matchUARules(collector, userAgentStyleSheet);
 
     // In quirks mode, we match rules from the quirks user agent sheet.
     if (document().inQuirksMode())
         matchUARules(collector, defaultStyleSheets.defaultQuirksStyle());
 
     // If document uses view source styles (in view source mode or in xml viewer mode), then we match rules from the view source style sheet.
     if (document().isViewSource())
         matchUARules(collector, defaultStyleSheets.defaultViewSourceStyle());
@@ skipping 1079 matching lines @@
     visitor->trace(m_features);
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingRules);
     visitor->trace(m_pendingStyleSheets);
 #endif
 }
 
 } // namespace blink