Implement BluetoothGattNotifySession::Stop on Android, 2nd attempt

device/bluetooth/bluetooth_gatt_notify_session.cc

 // Copyright 2014 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 "device/bluetooth/bluetooth_gatt_notify_session.h"
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "device/bluetooth/bluetooth_remote_gatt_characteristic.h"
+
 namespace device {
 
-BluetoothGattNotifySession::BluetoothGattNotifySession() {
+BluetoothGattNotifySession::BluetoothGattNotifySession(
+    base::WeakPtr<BluetoothRemoteGattCharacteristic> characteristic)
+    : characteristic_(characteristic),
+      characteristic_id_(characteristic.get() ? characteristic->GetIdentifier()
+                                              : std::string()),
+      active_(true) {}
+
+BluetoothGattNotifySession::~BluetoothGattNotifySession() {
+  if (active_) {
+    Stop(base::Bind(&base::DoNothing));
+  }
 }
 
-BluetoothGattNotifySession::~BluetoothGattNotifySession() {
+std::string BluetoothGattNotifySession::GetCharacteristicIdentifier() const {
+  return characteristic_id_;
+}
+
+BluetoothRemoteGattCharacteristic*
+BluetoothGattNotifySession::GetCharacteristic() const {
+  return characteristic_.get();
+}
+
+bool BluetoothGattNotifySession::IsActive() {
+  return active_ && characteristic_ != nullptr &&
+         characteristic_->IsNotifying();
+}
+
+void BluetoothGattNotifySession::Stop(const base::Closure& callback) {
+  active_ = false;
+  if (characteristic_ != nullptr) {
+    characteristic_->StopNotifySession(this, callback);
+  } else {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, callback);
+  }
 }
 
 }  // namespace device