Merge "Check for nullness in WallpaperService onDestroy" into udc-dev am: 1ce89ea1

            engineWrapper.destroy();

        }

        mActiveEngines.clear();

        if (mBackgroundThread != null) {

            // onDestroy might be called without a previous onCreate if WallpaperService was

            // instantiated manually. While this is a misuse of the API, some things break

            // if here we don't take into consideration this scenario.

            mBackgroundThread.quitSafely();

        }

        Trace.endSection();

    }