Elements using @apply shouldn't use the MatchedPropertiesCache

third_party/WebKit/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 1413 matching lines @@
         // When hitting matched properties' cache, only inherited properties will be
         // applied.
         if (inheritedOnly && !CSSPropertyMetadata::isInheritedProperty(propertyId))
             continue;
 
         StyleBuilder::applyProperty(propertyId, state, allValue);
     }
 }
 
 template <CSSPropertyPriority priority>
-void StyleResolver::applyPropertiesForApplyAtRule(StyleResolverState& state, const CSSValue& value, bool isImportant, bool inheritedOnly, PropertyWhitelistType propertyWhitelistType)
+void StyleResolver::applyPropertiesForApplyAtRule(StyleResolverState& state, const CSSValue& value, bool isImportant, PropertyWhitelistType propertyWhitelistType)
 {
+    if (!state.style()->hasVariableReferenceFromNonInheritedProperty())
+        state.style()->setHasVariableReferenceFromNonInheritedProperty();

[meade_UTC10, 2016/08/08 06:53:56]

Do you get much from checking this before setting? Looks like this just ensures
the boolean is set to true.

[Timothy Loh, 2016/08/08 07:03:12]

Mmm yeah I'll remove the check

     if (!state.style()->variables())
         return;
     const String& name = toCSSCustomIdentValue(value).value();
     const StylePropertySet* propertySet = state.customPropertySetForApplyAtRule(name);
+    bool inheritedOnly = false;
     if (propertySet)
         applyProperties<priority>(state, propertySet, isImportant, inheritedOnly, propertyWhitelistType);
 }
 
 template <CSSPropertyPriority priority>
 void StyleResolver::applyProperties(StyleResolverState& state, const StylePropertySet* properties, bool isImportant, bool inheritedOnly, PropertyWhitelistType propertyWhitelistType)
 {
     unsigned propertyCount = properties->propertyCount();
     for (unsigned i = 0; i < propertyCount; ++i) {
         StylePropertySet::PropertyReference current = properties->propertyAt(i);
         CSSPropertyID property = current.id();
 
         if (property == CSSPropertyApplyAtRule) {
-            applyPropertiesForApplyAtRule<priority>(state, current.value(), isImportant, inheritedOnly, propertyWhitelistType);
+            DCHECK(!inheritedOnly);
+            applyPropertiesForApplyAtRule<priority>(state, current.value(), isImportant, propertyWhitelistType);
             continue;
         }
 
         if (isImportant != current.isImportant())
             continue;
 
         if (property == CSSPropertyAll) {
             applyAllProperty<priority>(state, current.value(), inheritedOnly, propertyWhitelistType);
             continue;
         }
@@ skipping 279 matching lines @@
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingScopes);
     visitor->trace(m_styleSharingLists);
     visitor->trace(m_pendingStyleSheets);
     visitor->trace(m_document);
 }
 
 } // namespace blink