Defer pushing the parent stack in recalcStyle until StyleResolver::styleForElement()

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 45 matching lines @@
 #include "core/css/MediaQueryEvaluator.h"
 #include "core/css/PageRuleCollector.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/css/resolver/AnimatedStyleBuilder.h"
 #include "core/css/resolver/MatchResult.h"
 #include "core/css/resolver/MediaQueryResult.h"
 #include "core/css/resolver/SharedStyleFinder.h"
 #include "core/css/resolver/StyleAdjuster.h"
+#include "core/css/resolver/StyleResolverParentScope.h"
 #include "core/css/resolver/StyleResolverStats.h"
 #include "core/css/resolver/ViewportStyleResolver.h"
 #include "core/dom/CSSSelectorWatch.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/StyleEngine.h"
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 568 matching lines @@
             s_styleNotYetAvailable = RenderStyle::create().leakRef();
             s_styleNotYetAvailable->setDisplay(NONE);
             s_styleNotYetAvailable->font().update(document().styleEngine()->fontSelector());
         }
         element->document().setHasNodesWithPlaceholderStyle();
         return s_styleNotYetAvailable;
     }
 
     didAccess();
 
+    StyleResolverParentScope::ensureParentStackIsPushed();
+
     if (element == document().documentElement())
         resetDirectionAndWritingModeOnDocument(document());
     StyleResolverState state(document(), element, defaultParent);
 
     if (sharingBehavior == AllowStyleSharing && state.parentStyle()) {
         SharedStyleFinder styleFinder(state.elementContext(), m_features, m_siblingRuleSet.get(), m_uncommonAttributeRuleSet.get(), *this);
         if (RefPtr<RenderStyle> sharedStyle = styleFinder.findSharedStyle())
             return sharedStyle.release();
     }
 
@@ skipping 186 matching lines @@
         activeAnimations->cssAnimations().maybeApplyPendingUpdate(pseudo.get());
     return pseudo.release();
 }
 
 bool StyleResolver::pseudoStyleForElementInternal(Element& element, const PseudoStyleRequest& pseudoStyleRequest, RenderStyle* parentStyle, StyleResolverState& state)
 {
     ASSERT(document().frame());
     ASSERT(documentSettings());
     ASSERT(pseudoStyleRequest.pseudoId != FIRST_LINE_INHERITED);
 
+    StyleResolverParentScope::ensureParentStackIsPushed();
+
     if (pseudoStyleRequest.allowsInheritance(state.parentStyle())) {
         state.setStyle(RenderStyle::create());
         state.style()->inheritFrom(state.parentStyle());
     } else {
         state.setStyle(defaultStyleForElement());
         state.setParentStyle(RenderStyle::clone(state.style()));
     }
 
     state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
 
@@ skipping 553 matching lines @@
     visitor->trace(m_keyframesRuleMap);
     visitor->trace(m_viewportDependentMediaQueryResults);
     visitor->trace(m_viewportStyleResolver);
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingRules);
 }
 
 } // namespace WebCore