device/bluetooth: Update GATT descriptor value D-Bus bindings.

device/bluetooth/bluetooth_remote_gatt_descriptor_chromeos.h

 // 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.
 
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_REMOTE_GATT_DESCRIPTOR_CHROMEOS_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_REMOTE_GATT_DESCRIPTOR_CHROMEOS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 39 matching lines @@
   const dbus::ObjectPath& object_path() const { return object_path_; }
 
  private:
   friend class BluetoothRemoteGattCharacteristicChromeOS;
 
   BluetoothRemoteGattDescriptorChromeOS(
       BluetoothRemoteGattCharacteristicChromeOS* characteristic,
       const dbus::ObjectPath& object_path);
   virtual ~BluetoothRemoteGattDescriptorChromeOS();
 
-  // Called by dbus:: on completion of the request to get the descriptor value.
-  void OnGetValue(const ValueCallback& callback,
-                  const ErrorCallback& error_callback,
-                  bool success);
+  // Called by dbus:: on successful completion of a request to read
+  // the descriptor value.
+  void OnValueSuccess(const ValueCallback& callback,
+                      const std::vector<uint8>& value);
 
-  // Called by dbus:: on completion of the request to set the descriptor value.
-  void OnSetValue(const base::Closure& callback,
-                  const ErrorCallback& error_callback,
-                  bool success);
+  // Called by dbus:: on unsuccessful completion of a request to read or write
+  // the descriptor value.
+  void OnError(const ErrorCallback& error_callback,
+               const std::string& error_name,
+               const std::string& error_message);
 
   // Object path of the D-Bus descriptor object.
   dbus::ObjectPath object_path_;
 
   // The GATT characteristic this descriptor belongs to.
   BluetoothRemoteGattCharacteristicChromeOS* characteristic_;
 
+  // The cached characteristic value based on the most recent read request.
+  std::vector<uint8> cached_value_;
+
   // 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<BluetoothRemoteGattDescriptorChromeOS> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothRemoteGattDescriptorChromeOS);
 };
 
 }  // namespace chromeos
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_REMOTE_GATT_DESCRIPTOR_CHROMEOS_H_