Pass JavaRef to Java methods in device/bluetooth.

device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc b/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
index 594303773ae06602ff55644b2728cd34a7d0f7cc..ecab337479bf4658154ba0e97f6fd2e909b9422d 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
@@ -21,6 +21,7 @@
 
 using base::android::AttachCurrentThread;
 using base::android::JavaParamRef;
+using base::android::JavaRef;
 
 namespace device {
 
@@ -30,9 +31,10 @@ BluetoothRemoteGattCharacteristicAndroid::Create(
     BluetoothAdapterAndroid* adapter,
     BluetoothRemoteGattServiceAndroid* service,
     const std::string& instance_id,
-    jobject /* BluetoothGattCharacteristicWrapper */
+    const JavaRef<jobject>& /* BluetoothGattCharacteristicWrapper */
     bluetooth_gatt_characteristic_wrapper,
-    jobject /* ChromeBluetoothDevice */ chrome_bluetooth_device) {
+    const JavaRef<
+        jobject>& /* ChromeBluetoothDevice */ chrome_bluetooth_device) {
   std::unique_ptr<BluetoothRemoteGattCharacteristicAndroid> characteristic(
       new BluetoothRemoteGattCharacteristicAndroid(adapter, service,
                                                    instance_id));
@@ -243,7 +245,7 @@ void BluetoothRemoteGattCharacteristicAndroid::SubscribeToNotifications(
     const base::Closure& callback,
     const ErrorCallback& error_callback) {
   if (!Java_ChromeBluetoothRemoteGattCharacteristic_setCharacteristicNotification(
-          AttachCurrentThread(), j_characteristic_.obj(), true)) {
+          AttachCurrentThread(), j_characteristic_, true)) {
     LOG(ERROR) << "Error enabling characteristic notification";
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(error_callback,
@@ -263,7 +265,7 @@ void BluetoothRemoteGattCharacteristicAndroid::UnsubscribeFromNotifications(
     const base::Closure& callback,
     const ErrorCallback& error_callback) {
   if (!Java_ChromeBluetoothRemoteGattCharacteristic_setCharacteristicNotification(
-          AttachCurrentThread(), j_characteristic_.obj(), false)) {
+          AttachCurrentThread(), j_characteristic_, false)) {
     LOG(ERROR) << "Error disabling characteristic notification";
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,