Create NetworkQuietDetector.

third_party/WebKit/Source/core/loader/NetworkQuietDetector.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 NetworkQuietDetector_h
+#define NetworkQuietDetector_h
+
+#include "core/CoreExport.h"
+#include "core/dom/Document.h"
+#include "platform/Supplementable.h"
+#include "platform/Timer.h"
+#include "platform/heap/Handle.h"
+#include "platform/wtf/Noncopyable.h"
+
+namespace blink {
+
+class Document;
+
+// NetworkQuietDetector observes network request count everytime a load is
+// finshed after DOMContentLoadedEventEnd is fired, and signals a network
+// idleness signal to GRC when there are no more than 2 network connection
+// active in 1 second.
+class CORE_EXPORT NetworkQuietDetector
+    : public GarbageCollectedFinalized<NetworkQuietDetector>,
+      public Supplement<Document> {
+  WTF_MAKE_NONCOPYABLE(NetworkQuietDetector);
+  USING_GARBAGE_COLLECTED_MIXIN(NetworkQuietDetector);
+
+ public:
+  static NetworkQuietDetector& From(Document&);
+  virtual ~NetworkQuietDetector() {}
+
+  void CheckNetworkStable();
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  friend class NetworkQuietDetectorTest;
+
+  // The page is quiet if there are no more than 2 active network requests for
+  // this duration of time.
+  static constexpr double kNetworkQuietWindowSeconds = 1.0;
+  static constexpr int kNetworkQuietMaximumConnections = 2;
+
+  explicit NetworkQuietDetector(Document&);
+  int ActiveConnections();
+  void SetNetworkQuietTimers(int active_connections);
+  void NetworkQuietTimerFired(TimerBase*);
+
+  bool network_quiet_reached_ = false;
+  TaskRunnerTimer<NetworkQuietDetector> network_quiet_timer_;
+};
+
+}  // namespace blink
+
+#endif