src/vs/workbench/browser/parts/views/viewPane.ts/ViewWelcomeController/onDidChangeViewWelcomeContent
class ViewWelcomeController:	private onDidChangeViewWelcomeContent(): void {
		const descriptors = viewsRegistry.getViewWelcomeContent(this.id);

		this.items = [];

		for (const descriptor of descriptors) {
			if (descriptor.when === 'default') {
				this.defaultItem = { descriptor, visible: true };
			} else {
				const visible = descriptor.when ? this.contextKeyService.contextMatchesRules(descriptor.when) : true;
				this.items.push({ descriptor, visible });
			}
		}

		this._onDidChange.fire();
	}