Merge "Fix ConcurrentModificationException in QuickstepWidgetHolder" into udc-dev

                    i -> MAIN_EXECUTOR.execute(() ->

                            sHolders.forEach(h -> h.mAppWidgetRemovedCallback.accept(i))),

                    () -> MAIN_EXECUTOR.execute(() ->

                            sHolders.forEach(h -> h.mProviderChangedListeners.forEach(

                            sHolders.forEach(h ->

                                    // Listeners might remove themselves from the list during the

                                    // iteration. Creating a copy of the list to avoid exceptions

                                    // for concurrent modification.

                                    new ArrayList<>(h.mProviderChangedListeners).forEach(

                                    ProviderChangedListener::notifyWidgetProvidersChanged))),

                    UI_HELPER_EXECUTOR.getLooper());

            if (!WidgetsModel.GO_DISABLE_WIDGETS) {