Add a deprecation message for shadow-piercing descendant combinators and shadow pseudo elements.

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 380 matching lines @@
         nextContext.inRightmostCompound = false;
         for (; nextContext.element; nextContext.element = ElementTraversal::previousSibling(*nextContext.element)) {
             Match match = matchSelector(nextContext, result);
             if (match == SelectorMatches || match == SelectorFailsAllSiblings || match == SelectorFailsCompletely)
                 return match;
         };
         return SelectorFailsAllSiblings;
 
     case CSSSelector::ShadowPseudo:
         {
+            if (!context.isUARule && context.selector->pseudoType() == CSSSelector::PseudoShadow)
+                UseCounter::countDeprecation(context.element->document(), UseCounter::CSSSelectorPseudoShadow);
             // If we're in the same tree-scope as the scoping element, then following a shadow descendant combinator would escape that and thus the scope.
             if (context.scope && context.scope->shadowHost() && context.scope->shadowHost()->treeScope() == context.element->treeScope())
                 return SelectorFailsCompletely;
 
             Element* shadowHost = context.element->shadowHost();
             if (!shadowHost)
                 return SelectorFailsCompletely;
             nextContext.element = shadowHost;
             nextContext.isSubSelector = false;
             nextContext.inRightmostCompound = false;
             return matchSelector(nextContext, result);
         }
 
     case CSSSelector::ShadowDeep:
         {
+            if (!context.isUARule)
+                UseCounter::countDeprecation(context.element->document(), UseCounter::CSSDeepCombinator);
             if (ShadowRoot* root = context.element->containingShadowRoot()) {
                 if (root->type() == ShadowRoot::UserAgentShadowRoot)
                     return SelectorFailsCompletely;
             }
 
             if (context.selector->relationIsAffectedByPseudoContent()) {
                 for (Element* element = context.element; element; element = element->parentOrShadowHostElement()) {
                     if (matchForShadowDistributed(nextContext, *element, result) == SelectorMatches)
                         return SelectorMatches;
                 }
@@ skipping 749 matching lines @@
 }
 
 bool SelectorChecker::matchesFocusPseudoClass(const Element& element)
 {
     if (InspectorInstrumentation::forcePseudoState(const_cast<Element*>(&element), CSSSelector::PseudoFocus))
         return true;
     return element.focused() && isFrameFocused(element);
 }
 
 }