Move the CSS Device Adaptation @viewport rule support behind a runtime flag

Source/core/css/RuleSet.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 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 15 matching lines @@
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/css/RuleSet.h"
 
 #include <wtf/MemoryInstrumentationHashMap.h>
 #include <wtf/MemoryInstrumentationHashSet.h>
 #include <wtf/MemoryInstrumentationVector.h>
 #include "HTMLNames.h"
+#include "RuntimeEnabledFeatures.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/css/CSSKeyframesRule.h"
 #include "core/css/CSSSelector.h"
 #include "core/css/CSSSelectorList.h"
 #include "core/css/MediaQueryEvaluator.h"
 #include "core/css/SelectorChecker.h"
 #include "core/css/SelectorCheckerFastPath.h"
 #include "core/css/SelectorFilter.h"
 #include "core/css/StyleRule.h"
 #include "core/css/StyleRuleImport.h"
@@ skipping 288 matching lines @@
             if (!isDocumentScope(scope))
                 continue;
             resolver->addKeyframeStyle(static_cast<StyleRuleKeyframes*>(rule));
         }
         else if (rule->isRegionRule() && resolver) {
             // FIXME (BUG 72472): We don't add @-webkit-region rules of scoped style sheets for the moment.
             addRegionRule(static_cast<StyleRuleRegion*>(rule), hasDocumentSecurityOrigin);
         }
         else if (rule->isHostRule())
             resolver->ensureScopedStyleResolver(scope->shadowHost())->addHostRule(static_cast<StyleRuleHost*>(rule), hasDocumentSecurityOrigin, scope);
-#if ENABLE(CSS_DEVICE_ADAPTATION)
-        else if (rule->isViewportRule() && resolver) {
+        else if (RuntimeEnabledFeatures::cssViewportEnabled() && rule->isViewportRule() && resolver) {
             // @viewport should not be scoped.
             if (!isDocumentScope(scope))
                 continue;
             resolver->viewportStyleResolver()->addViewportRule(static_cast<StyleRuleViewport*>(rule));
         }
-#endif
         else if (rule->isSupportsRule() && static_cast<StyleRuleSupports*>(rule)->conditionIsSupported())
             addChildRules(static_cast<StyleRuleSupports*>(rule)->childRules(), medium, resolver, scope, hasDocumentSecurityOrigin, addRuleFlags);
     }
 }
 
 void RuleSet::addRulesFromSheet(StyleSheetContents* sheet, const MediaQueryEvaluator& medium, StyleResolver* resolver, const ContainerNode* scope)
 {
     ASSERT(sheet);
 
     const Vector<RefPtr<StyleRuleImport> >& importRules = sheet->importRules();
@@ skipping 32 matching lines @@
     shrinkMapVectorsToFit(m_tagRules);
     shrinkMapVectorsToFit(m_shadowPseudoElementRules);
     m_linkPseudoClassRules.shrinkToFit();
     m_cuePseudoRules.shrinkToFit();
     m_focusPseudoClassRules.shrinkToFit();
     m_universalRules.shrinkToFit();
     m_pageRules.shrinkToFit();
 }
 
 } // namespace WebCore