First version of PerformanceObserver

Source/core/timing/PerformanceObserverRegistration.h

+/*
+ * Copyright (C) 2015 Google 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+ * OWNER OR 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.
+ */
+
+#ifndef PerformanceObserverRegistration_h
+#define PerformanceObserverRegistration_h
+
+#include "core/timing/PerformanceObserver.h"
+#include "platform/heap/Handle.h"
+#include "wtf/HashSet.h"
+#include "wtf/text/AtomicString.h"
+#include "wtf/text/AtomicStringHash.h"
+
+namespace blink {
+
+class PerformanceBase;
+
+class PerformanceObserverRegistration final : public GarbageCollectedFinalized<PerformanceObserverRegistration> {
+public:
+    static PerformanceObserverRegistration* create(PerformanceObserver&, PerformanceBase*, const HashSet<AtomicString>& typeFilter);

[esprehn, 2015/07/18 22:24:16]

Why the PerformanceBase argument? The observer should know what performance it
belongs to

[MikeB, 2015/07/20 23:06:50]

Got rid of this class entirely. Simplifies things a bit. PerformanceObserver now
has no reason to track multiple Performance targets, so we can drop it.

+    ~PerformanceObserverRegistration();
+
+    void resetObservation(const HashSet<AtomicString>& typeFilter);
+
+    void unregister();
+
+    PerformanceObserver& observer() const { return *m_observer; }
+    PerformanceBase* performance() const { return m_performance.get(); }

[esprehn, 2015/07/18 22:24:16]

Can this be null? i don't think it can, you want *m_observer

+
+    DECLARE_TRACE();
+
+    void dispose();
+
+    void addReference() { ++m_referenceCount; }

[esprehn, 2015/07/18 22:24:16]

This manual reference count is very weird, what are you trying to do here? If
you do need this you want this to be RefCounted, but the GC thing should remove
the need for that. maybe you want Weak references to this somewhere?

+
+    bool shouldReceiveEntryFrom(const AtomicString& typeName) const;
+
+private:
+    PerformanceObserverRegistration(PerformanceObserver&, PerformanceBase*, const HashSet<AtomicString>& typeFilter);
+
+    Member<PerformanceObserver> m_observer;
+    WeakMember<PerformanceBase> m_performance;

[esprehn, 2015/07/18 22:24:16]

the observer should know the performance.

+
+    HashSet<AtomicString> m_typeFilter;

[esprehn, 2015/07/18 22:24:17]

This should be an unsigned bitfield where each bit is a different type.

+    unsigned m_referenceCount;
+};
+
+} // namespace blink
+
+#endif // PerformanceObserverRegistration_h