Enable ServerTiming support

third_party/WebKit/Source/core/timing/PerformanceServerTiming.h

+// Copyright 2017 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 PerformanceServerTiming_h
+#define PerformanceServerTiming_h
+
+#include "core/timing/PerformanceEntry.h"
+
+namespace blink {
+
+class CORE_EXPORT PerformanceServerTiming : public PerformanceEntry {
+  DEFINE_WRAPPERTYPEINFO();
+
+ public:
+  ~PerformanceServerTiming() override;
+
+  static PerformanceServerTiming* create(const String& name,
+                                         const String& metric,
+                                         double duration,
+                                         const String& description) {
+    return new PerformanceServerTiming(name, metric, duration, description);
+  }
+
+  String metric() const;
+  String description() const;
+
+ protected:
+  void buildJSONValue(V8ObjectBuilder&) const override;
+
+ private:
+  PerformanceServerTiming(const String& name,
+                          const String& metric,
+                          double duration,
+                          const String& description);
+
+  const String m_metric;
+  const String m_description;
+};
+
+}  // namespace blink
+
+#endif  // PerformanceServerTiming_h