1 files changed, 68 insertions, 0 deletions
diff --git a/Source/WebCore/style/IdChangeInvalidation.h b/Source/WebCore/style/IdChangeInvalidation.h
new file mode 100644
index 000000000..0e3bdef9b
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+++ b/Source/WebCore/style/IdChangeInvalidation.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Element.h"
+
+namespace WebCore {
+
+namespace Style {
+
+class IdChangeInvalidation {
+public:
+    IdChangeInvalidation(Element&, const AtomicString& oldId, const AtomicString& newId);
+    ~IdChangeInvalidation();
+
+private:
+    void invalidateStyle(const AtomicString&);
+
+    const bool m_isEnabled;
+    Element& m_element;
+
+    AtomicString m_newId;
+};
+
+inline IdChangeInvalidation::IdChangeInvalidation(Element& element, const AtomicString& oldId, const AtomicString& newId)
+    : m_isEnabled(element.needsStyleInvalidation())
+    , m_element(element)
+{
+    if (!m_isEnabled)
+        return;
+    if (oldId == newId)
+        return;
+    m_newId = newId;
+    invalidateStyle(oldId);
+}
+
+inline IdChangeInvalidation::~IdChangeInvalidation()
+{
+    if (!m_isEnabled)
+        return;
+    invalidateStyle(m_newId);
+}
+
+}
+}