Better counting of /deep/ usage

third_party/WebKit/Source/core/css/SelectorChecker.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 357 matching lines @@
 
     case CSSSelector::ShadowDeep:
         {
             if (!m_isUARule && !m_isQuerySelector)
                 Deprecation::countDeprecation(context.element->document(), UseCounter::CSSDeepCombinator);
             if (ShadowRoot* root = context.element->containingShadowRoot()) {
                 if (root->type() == ShadowRootType::UserAgent)
                     return SelectorFailsCompletely;
             }
 
+
             if (context.selector->relationIsAffectedByPseudoContent()) {
                 // TODO(kochi): closed mode tree should be handled as well for ::content.
                 for (Element* element = context.element; element; element = element->parentOrShadowHostElement()) {
-                    if (matchForPseudoContent(nextContext, *element, result) == SelectorMatches)
+                    if (matchForPseudoContent(nextContext, *element, result) == SelectorMatches) {
+                        if (context.element->isInShadowTree())
+                            UseCounter::count(context.element->document(), UseCounter::CSSDeepCombinatorAndShadow);
                         return SelectorMatches;
+                    }
                 }
                 return SelectorFailsCompletely;
             }
 
             for (nextContext.element = parentOrV0ShadowHostElement(*context.element); nextContext.element; nextContext.element = parentOrV0ShadowHostElement(*nextContext.element)) {
                 Match match = matchSelector(nextContext, result);
+                if (match == SelectorMatches && context.element->isInShadowTree())
+                    UseCounter::count(context.element->document(), UseCounter::CSSDeepCombinatorAndShadow);
                 if (match == SelectorMatches || match == SelectorFailsCompletely)
                     return match;
                 if (nextSelectorExceedsScope(nextContext))
                     return SelectorFailsCompletely;
             }
             return SelectorFailsCompletely;
         }
 
     case CSSSelector::ShadowSlot:
         {
@@ skipping 752 matching lines @@
 }
 
 bool SelectorChecker::matchesFocusPseudoClass(const Element& element)
 {
     if (InspectorInstrumentation::forcePseudoState(const_cast<Element*>(&element), CSSSelector::PseudoFocus))
         return true;
     return element.focused() && isFrameFocused(element);
 }
 
 } // namespace blink