Remove IsPointerConvertible trait and hacks and just use std::is_base_of.

third_party/WebKit/Source/core/css/SelectorChecker.cpp

Index: third_party/WebKit/Source/core/css/SelectorChecker.cpp
diff --git a/third_party/WebKit/Source/core/css/SelectorChecker.cpp b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
index ca0c2f910cfa887e1ae08980b7cdf91b3227c41c..1f1f39e7910fa5f18af21bce83bf40ad6f580dd4 100644
--- a/third_party/WebKit/Source/core/css/SelectorChecker.cpp
+++ b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
@@ -964,9 +964,9 @@ bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context, M
     case CSSSelector::PseudoScope:
         if (m_mode == SharingRules)
             return true;
-        if (context.scope == element.document())
+        if (context.scope == &element.document())
             return element == element.document().documentElement();
-        return context.scope == element;
+        return context.scope == &element;
     case CSSSelector::PseudoUnresolved:
         return element.isUnresolvedCustomElement();
     case CSSSelector::PseudoHost: