Implement a simple version of SelectorQuery.

third_party/WebKit/Source/core/dom/query/SelectorCheckerMatcher.h

Index: third_party/WebKit/Source/core/dom/query/SelectorCheckerMatcher.h
diff --git a/third_party/WebKit/Source/core/dom/query/SelectorCheckerMatcher.h b/third_party/WebKit/Source/core/dom/query/SelectorCheckerMatcher.h
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index 0000000000000000000000000000000000000000..73da539f651860b4ef37715ee9c07cf50119a9f0
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+++ b/third_party/WebKit/Source/core/dom/query/SelectorCheckerMatcher.h
@@ -0,0 +1,29 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SelectorCheckerMatcher_h
+#define SelectorCheckerMatcher_h
+
+#include "core/css/CSSSelectorList.h"
+#include "core/dom/query/SelectorMatcher.h"
+
+namespace blink {
+
+class SelectorCheckerMatcher final : public SelectorMatcher {
+public:
+    explicit SelectorCheckerMatcher(CSSSelectorList&);
+    ~SelectorCheckerMatcher() override;
+
+    Element* findFirst(ContainerNode& rootNode) const override;
+    void findAll(ContainerNode& rootNode, WillBeHeapVector<RefPtrWillBeMember<Element>>& result) const override;
+    bool match(Element&, ContainerNode& rootNode) const override;
+private:
+    CSSSelectorList m_selectorList;
+    bool m_usesDeepCombinatorOrShadowPseudo : 1;
+    bool m_needsUpdatedDistribution : 1;
+};
+
+}
+
+#endif