bluetooth: Check if device name is null before trying to convert

device/bluetooth/bluetooth_device_android.cc

 // Copyright 2015 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.
 
 #include "device/bluetooth/bluetooth_device_android.h"
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
@@ skipping 263 matching lines @@
               GetAndroidAdapter(), this, bluetooth_gatt_service_wrapper,
               instance_id_string, j_device_.obj()));
 
   adapter_->NotifyGattServiceAdded(service_iterator->second);
 }
 
 BluetoothDeviceAndroid::BluetoothDeviceAndroid(BluetoothAdapterAndroid* adapter)
     : BluetoothDevice(adapter) {}
 
 std::string BluetoothDeviceAndroid::GetDeviceName() const {
-  return ConvertJavaStringToUTF8(Java_ChromeBluetoothDevice_getDeviceName(
-      AttachCurrentThread(), j_device_.obj()));
+  auto device_name = Java_ChromeBluetoothDevice_getDeviceName(
+      AttachCurrentThread(), j_device_.obj());
+
+  if (device_name.is_null()) {
+    return "";
+  }
+  return ConvertJavaStringToUTF8(device_name);
 }
 
 void BluetoothDeviceAndroid::CreateGattConnectionImpl() {
   Java_ChromeBluetoothDevice_createGattConnectionImpl(
       AttachCurrentThread(), j_device_.obj(),
       base::android::GetApplicationContext());
 }
 
 void BluetoothDeviceAndroid::DisconnectGatt() {
   Java_ChromeBluetoothDevice_disconnectGatt(AttachCurrentThread(),
                                             j_device_.obj());
 }
 
 }  // namespace device