[Easy Unlock] Port the BluetoothThrottler class to native code.

components/proximity_auth/throttled_bluetooth_connection_finder.h

+// 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 COMPONENTS_PROXIMITY_AUTH_THROTTLED_BLUETOOTH_CONNECTION_FINDER_H
+#define COMPONENTS_PROXIMITY_AUTH_THROTTLED_BLUETOOTH_CONNECTION_FINDER_H
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "components/proximity_auth/connection_finder.h"
+#include "components/proximity_auth/connection_observer.h"
+
+namespace base {
+class TaskRunner;
+}
+
+namespace proximity_auth {
+
+class BluetoothConnectionFinder;
+class BluetoothThrottler;
+class Connection;
+
+// A Bluetooth connection finder that delays Find() requests according to the
+// throttler's cooldown period.
+class ThrottledBluetoothConnectionFinder : public ConnectionFinder,
+                                           public ConnectionObserver {
+ public:
+  // Note: The |throttler| is not owned, and must outlive |this| instance.
+  ThrottledBluetoothConnectionFinder(
+      scoped_ptr<BluetoothConnectionFinder> connection_finder,
+      scoped_refptr<base::TaskRunner> task_runner,
+      BluetoothThrottler* throttler);
+  ~ThrottledBluetoothConnectionFinder() override;
+
+  // ConnectionFinder:
+  void Find(const ConnectionCallback& connection_callback) override;
+
+ private:
+  // Callback to be called when a connection is found.
+  void OnConnection(const ConnectionCallback& connection_callback,
+                    scoped_ptr<Connection> connection);
+
+  // ConnectionObserver:
+  void OnConnectionStatusChanged(const Connection& connection,
+                                 Connection::Status old_status,
+                                 Connection::Status new_status) override;
+
+  // The underlying connection finder.
+  scoped_ptr<BluetoothConnectionFinder> connection_finder_;
+
+  // The task runner used for posting delayed messages.
+  scoped_refptr<base::TaskRunner> task_runner_;
+
+  // The throttler managing this connection finder. The throttler is not owned,
+  // and must outlive |this| instance.
+  BluetoothThrottler* throttler_;
+
+  // The found connection; null if no connection has yet been found.
+  // Stored as a weak reference, which is safe because |this| instance is
+  // registered as an observer, and will unregister when the connection
+  // disconnects, which is guaranteed to occur before the connection is
+  // destroyed.
+  Connection* connection_;
+
+  base::WeakPtrFactory<ThrottledBluetoothConnectionFinder> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThrottledBluetoothConnectionFinder);
+};
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_THROTTLED_BLUETOOTH_CONNECTION_FINDER_H