First version of PerformanceObserver

Source/core/timing/PerformanceObserver.h

Index: Source/core/timing/PerformanceObserver.h
diff --git a/Source/core/timing/PerformanceObserver.h b/Source/core/timing/PerformanceObserver.h
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+// 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 PerformanceObserver_h
+#define PerformanceObserver_h
+
+#include "bindings/core/v8/ScriptWrappable.h"
+#include "core/timing/PerformanceEntry.h"
+#include "platform/heap/Handle.h"
+#include "wtf/HashSet.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RefCounted.h"
+#include "wtf/RefPtr.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+class ExceptionState;
+class PerformanceBase;
+class PerformanceObserverCallback;
+class PerformanceObserver;
+class PerformanceObserverInit;
+
+using PerformanceEntryVector = HeapVector<Member<PerformanceEntry>>;
+
+class PerformanceObserver final : public GarbageCollectedFinalized<PerformanceObserver>, public ScriptWrappable {
+    DEFINE_WRAPPERTYPEINFO();
+    friend class PerformanceBase;
+public:
+    static PerformanceObserver* create(PerformanceBase*, PerformanceObserverCallback*);
+    static void resumeSuspendedObservers();
+
+    ~PerformanceObserver();
+
+    void observe(const PerformanceObserverInit&, ExceptionState&);
+    void disconnect();
+    void enqueuePerformanceEntry(PerformanceEntry&);
+    PerformanceEntryTypeMask filterOptions() const { return m_filterOptions; }
+
+    // Eagerly finalized as destructor accesses heap object members.
+    EAGERLY_FINALIZE();
+    DECLARE_TRACE();
+
+private:
+    explicit PerformanceObserver(PerformanceBase*, PerformanceObserverCallback*);
+    void deliver();
+    bool shouldBeSuspended() const;
+
+    Member<PerformanceObserverCallback> m_callback;
+    WeakMember<PerformanceBase> m_performance;
+    PerformanceEntryVector m_performanceEntries;
+    PerformanceEntryTypeMask m_filterOptions;
+    bool m_isRegistered;
+};
+
+} // namespace blink
+
+#endif // PerformanceObserver_h