Fix getting notified twice after subscribe to notifications and call readValue

device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.cc

 // Copyright 2016 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/bluez/bluetooth_remote_gatt_characteristic_bluez.h"
 
 #include <iterator>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 27 matching lines @@
 }
 
 }  // namespace
 
 BluetoothRemoteGattCharacteristicBlueZ::BluetoothRemoteGattCharacteristicBlueZ(
     BluetoothRemoteGattServiceBlueZ* service,
     const dbus::ObjectPath& object_path)
     : BluetoothGattCharacteristicBlueZ(object_path),
       has_notify_session_(false),
       service_(service),
+      characteristic_value_read_in_progress_(false),
       weak_ptr_factory_(this) {
   VLOG(1) << "Creating remote GATT characteristic with identifier: "
           << GetIdentifier() << ", UUID: " << GetUUID().canonical_value();
   bluez::BluezDBusManager::Get()
       ->GetBluetoothGattDescriptorClient()
       ->AddObserver(this);
 
   // Add all known GATT characteristic descriptors.
   const std::vector<dbus::ObjectPath>& gatt_descs =
       bluez::BluezDBusManager::Get()
@@ skipping 119 matching lines @@
   return iter->second;
 }
 
 void BluetoothRemoteGattCharacteristicBlueZ::ReadRemoteCharacteristic(
     const ValueCallback& callback,
     const ErrorCallback& error_callback) {
   VLOG(1) << "Sending GATT characteristic read request to characteristic: "
           << GetIdentifier() << ", UUID: " << GetUUID().canonical_value()
           << ".";
 
+  characteristic_value_read_in_progress_ = true;

[ortuno, 2017/03/03 05:28:37]

If the read fails then this never goes back to false. Could you write or update
current tests to make sure we are doing the right thing?

[juncai, 2017/03/04 01:33:59]

Done.

+
   bluez::BluezDBusManager::Get()
       ->GetBluetoothGattCharacteristicClient()
       ->ReadValue(object_path(), callback,
                   base::Bind(&BluetoothRemoteGattCharacteristicBlueZ::OnError,
                              weak_ptr_factory_.GetWeakPtr(), error_callback));
 }
 
 void BluetoothRemoteGattCharacteristicBlueZ::WriteRemoteCharacteristic(
     const std::vector<uint8_t>& value,
     const base::Closure& callback,
@@ skipping 160 matching lines @@
     const ErrorCallback& error_callback,
     const std::string& error_name,
     const std::string& error_message) {
   VLOG(1) << "Operation failed: " << error_name
           << ", message: " << error_message;
   error_callback.Run(
       BluetoothGattServiceBlueZ::DBusErrorToServiceError(error_name));
 }
 
 }  // namespace bluez