chromeos/dbus: Update Bluetooth GATT API clients to upstream definition

chromeos/dbus/bluetooth_gatt_descriptor_client.h

Index: chromeos/dbus/bluetooth_gatt_descriptor_client.h
diff --git a/chromeos/dbus/bluetooth_gatt_descriptor_client.h b/chromeos/dbus/bluetooth_gatt_descriptor_client.h
index c3f24ac4ba2fdc1bdb0ba400892134cbb046657c..e324d13b009d9ebd19e8750af4f6f12adf77b321 100644
--- a/chromeos/dbus/bluetooth_gatt_descriptor_client.h
+++ b/chromeos/dbus/bluetooth_gatt_descriptor_client.h
@@ -6,6 +6,7 @@
 #define CHROMEOS_DBUS_BLUETOOTH_GATT_DESCRIPTOR_CLIENT_H_
 
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
@@ -29,6 +30,10 @@ class CHROMEOS_EXPORT BluetoothGattDescriptorClient : public DBusClient {
     // [read-only]
     dbus::Property<dbus::ObjectPath> characteristic;
 
+    // The cached value of the descriptor. This property gets updated only after
+    // a successful read request. [read-only]
+    dbus::Property<std::vector<uint8_t>> value;
+
     Properties(dbus::ObjectProxy* object_proxy,
                const std::string& interface_name,
                const PropertyChangedCallback& callback);