Merge "Workaround for wallpapers render thread been paused while visible." into sc-dev

        private void doDetachEngine() {

            mActiveEngines.remove(mEngine);

            mEngine.detach();

            // Some wallpapers will not trigger the rendering threads of the remaining engines even

            // if they are visible, so we need to toggle the state to get their attention.

            if (!mDetached.get()) {

                for (Engine eng : mActiveEngines) {

                    if (eng.mVisible) {

                        eng.doVisibilityChanged(false);

                        eng.doVisibilityChanged(true);

                    }

                }

            }

        }

        @Override