src/vs/platform/userDataSync/common/ignoredExtensions.ts/IgnoredExtensionsManagementService/getConfiguredIgnoredExtensions
class IgnoredExtensionsManagementService:	private getConfiguredIgnoredExtensions(): ReadonlyArray<string> {
		let userValue = this.configurationService.inspect<string[]>('settingsSync.ignoredExtensions').userValue;
		if (userValue !== undefined) {
			return userValue;
		}
		userValue = this.configurationService.inspect<string[]>('sync.ignoredExtensions').userValue;
		if (userValue !== undefined) {
			return userValue;
		}
		return (this.configurationService.getValue<string[]>('settingsSync.ignoredExtensions') || []).map(id => id.toLowerCase());
	}