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

chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h

Index: chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h
diff --git a/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h
index f93bc74a13476f3a0470bceb8eac2184ddb1f904..3934a4c0f9bed0ec39b94d01573f58e0d99d2e51 100644
--- a/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h
+++ b/chromeos/dbus/fake_bluetooth_gatt_characteristic_client.h
@@ -128,6 +128,12 @@ class CHROMEOS_EXPORT FakeBluetoothGattCharacteristicClient
   // is a random value within a reasonable range.
   std::vector<uint8> GetHeartRateMeasurementValue();
 
+  // Callback that executes a delayed ReadValue action by updating the
+  // appropriate "Value" property and invoking the ValueCallback.
+  void DelayedReadValueCallback(const dbus::ObjectPath& object_path,
+                                const ValueCallback& callback,
+                                const std::vector<uint8_t>& value);
+
   // If true, characteristics of the Heart Rate Service are visible. Use
   // IsHeartRateVisible() to check the value.
   bool heart_rate_visible_;