src/vs/workbench/contrib/extensions/browser/extensionsViewlet.ts/ExtensionsViewPaneContainer/onDidAddViewDescriptors
class ExtensionsViewPaneContainer:	protected override onDidAddViewDescriptors(added: IAddedViewDescriptorRef[]): ViewPane[] {
		const addedViews = super.onDidAddViewDescriptors(added);
		this.progress(Promise.all(addedViews.map(addedView =>
			(<ExtensionsListView>addedView).show(this.normalizedQuery())
				.then(model => this.alertSearchResult(model.length, addedView.id))
		)));
		return addedViews;
	}