Fix getting notified twice after subscribe to notifications and call readValue

device/bluetooth/bluetooth_remote_gatt_characteristic_mac.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_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_MAC_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_MAC_H_
 
 #include "device/bluetooth/bluetooth_remote_gatt_characteristic.h"
 
 #include <unordered_map>
@@ skipping 56 matching lines @@
 
  private:
   friend class BluetoothRemoteGattDescriptorMac;
   friend class BluetoothRemoteGattServiceMac;
   friend class BluetoothTestMac;
 
   void DiscoverDescriptors();
   // Called by the BluetoothRemoteGattServiceMac instance when the
   // characteristics value has been read.
   void DidUpdateValue(NSError* error);
-  // Updates value_ and notifies the adapter of the new value.
-  void UpdateValueAndNotify();
+  // Updates value_.
+  void UpdateValue();
   // Called by the BluetoothRemoteGattServiceMac instance when the
   // characteristics value has been written.
   void DidWriteValue(NSError* error);
   // Called by the BluetoothRemoteGattServiceMac instance when the notify
   // session has been started or failed to be started.
   void DidUpdateNotificationState(NSError* error);
   // Called by the BluetoothRemoteGattServiceMac instance when the descriptors
   // has been discovered.
   void DidDiscoverDescriptors();
   // Returns true if the characteristic is readable.
@@ skipping 42 matching lines @@
   PendingNotifyCallbacks unsubscribe_from_notification_callbacks_;
   // Map of descriptors, keyed by descriptor identifier.
   std::unordered_map<std::string,
                      std::unique_ptr<BluetoothRemoteGattDescriptorMac>>
       gatt_descriptor_macs_;
 };
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_REMOTE_GATT_CHARACTERISTIC_MAC_H_