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

components/proximity_auth/bluetooth_throttler_impl.cc

+// 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.
+
+#include "components/proximity_auth/bluetooth_throttler_impl.h"
+
+#include "base/stl_util.h"
+#include "base/time/tick_clock.h"
+#include "components/proximity_auth/connection.h"
+
+namespace proximity_auth {
+namespace {
+
+// Time to wait after disconnect before reconnecting.
+const int kCooldownTimeSecs = 7;
+
+}  // namespace
+
+BluetoothThrottlerImpl::BluetoothThrottlerImpl(
+    scoped_ptr<base::TickClock> clock)
+    : clock_(clock.Pass()) {
+}
+
+BluetoothThrottlerImpl::~BluetoothThrottlerImpl() {
+  for (Connection* connection : connections_) {
+    connection->RemoveObserver(this);
+  }
+}
+
+base::TimeDelta BluetoothThrottlerImpl::GetDelay() const {
+  if (last_disconnect_time_.is_null())
+    return base::TimeDelta();
+
+  base::TimeTicks now = clock_->NowTicks();
+  base::TimeTicks throttled_start_time =
+      last_disconnect_time_ + GetCooldownTimeDelta();
+  if (now >= throttled_start_time)
+    return base::TimeDelta();
+
+  return throttled_start_time - now;
+}
+
+void BluetoothThrottlerImpl::OnConnection(Connection* connection) {
+  DCHECK(!ContainsKey(connections_, connection));
+  connections_.insert(connection);
+  connection->AddObserver(this);
+}
+
+base::TimeDelta BluetoothThrottlerImpl::GetCooldownTimeDelta() const {
+  return base::TimeDelta::FromSeconds(kCooldownTimeSecs);
+}
+
+void BluetoothThrottlerImpl::OnConnectionStatusChanged(
+    Connection* connection,
+    Connection::Status old_status,
+    Connection::Status new_status) {
+  DCHECK(ContainsKey(connections_, connection));
+  if (old_status == Connection::CONNECTED &&
+      new_status == Connection::DISCONNECTED) {
+    last_disconnect_time_ = clock_->NowTicks();
+    connection->RemoveObserver(this);
+    connections_.erase(connection);
+  }
+}
+
+}  // namespace proximity_auth