Support for CSSOM CSSNamespaceRule interface

Source/core/css/CSSNamespaceRule.cpp

Index: Source/core/css/CSSNamespaceRule.cpp
diff --git a/Source/core/css/CSSNamespaceRule.cpp b/Source/core/css/CSSNamespaceRule.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6525371e93de8920879c0406a2133e7ecd215b32
--- /dev/null
+++ b/Source/core/css/CSSNamespaceRule.cpp
@@ -0,0 +1,53 @@
+// 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.
+
+#include "config.h"
+#include "core/css/CSSNamespaceRule.h"
+
+#include "core/css/CSSMarkup.h"
+#include "core/css/StyleRuleNamespace.h"
+#include "wtf/text/StringBuilder.h"
+
+namespace blink {
+
+CSSNamespaceRule::CSSNamespaceRule(StyleRuleNamespace* namespaceRule, CSSStyleSheet* parent)
+    : CSSRule(parent)
+    , m_namespaceRule(namespaceRule)
+{
+}
+
+CSSNamespaceRule::~CSSNamespaceRule()
+{
+}
+
+String CSSNamespaceRule::cssText() const
+{
+    StringBuilder result;
+    result.appendLiteral("@namespace ");
+    serializeIdentifier(prefix(), result);
+    if (!prefix().isEmpty())
+        result.appendLiteral(" ");
+    result.appendLiteral("url(");
+    result.append(serializeString(namespaceURI()));
+    result.appendLiteral(");");
+    return result.toString();
+}
+
+AtomicString CSSNamespaceRule::namespaceURI() const
+{
+    return m_namespaceRule->uri();
+}
+
+AtomicString CSSNamespaceRule::prefix() const
+{
+    return m_namespaceRule->prefix();
+}
+
+DEFINE_TRACE(CSSNamespaceRule)
+{
+    visitor->trace(m_namespaceRule);
+    CSSRule::trace(visitor);
+}
+
+} // namespace blink