Fix getting notified twice after subscribe to notifications and call readValue

device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h

 // 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.
 
 #ifndef DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_BLUEZ_H_
 #define DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_BLUEZ_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <map>
@@ skipping 45 matching lines @@
   std::vector<device::BluetoothRemoteGattDescriptor*> GetDescriptors()
       const override;
   device::BluetoothRemoteGattDescriptor* GetDescriptor(
       const std::string& identifier) const override;
   void ReadRemoteCharacteristic(const ValueCallback& callback,
                                 const ErrorCallback& error_callback) override;
   void WriteRemoteCharacteristic(const std::vector<uint8_t>& value,
                                  const base::Closure& callback,
                                  const ErrorCallback& error_callback) override;
 
+  bool characteristic_value_read_in_progress() {
+    return characteristic_value_read_in_progress_;
+  }
+
+  void set_characteristic_value_read_in_progress(bool in_progress) {
+    characteristic_value_read_in_progress_ = in_progress;
+  }
+
  protected:
   void SubscribeToNotifications(
       device::BluetoothRemoteGattDescriptor* ccc_descriptor,
       const base::Closure& callback,
       const ErrorCallback& error_callback) override;
   void UnsubscribeFromNotifications(
       device::BluetoothRemoteGattDescriptor* ccc_descriptor,
       const base::Closure& callback,
       const ErrorCallback& error_callback) override;
 
@@ skipping 50 matching lines @@
 
   // Mapping from GATT descriptor object paths to descriptor objects owned by
   // this characteristic. Since the BlueZ implementation uses object paths
   // as unique identifiers, we also use this mapping to return descriptors by
   // identifier.
   DescriptorMap descriptors_;
 
   // The GATT service this GATT characteristic belongs to.
   BluetoothRemoteGattServiceBlueZ* service_;
 
+  // True if a gatt read request is in progress.
+  bool characteristic_value_read_in_progress_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<BluetoothRemoteGattCharacteristicBlueZ>
       weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothRemoteGattCharacteristicBlueZ);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_BLUEZ_H_