7 string references to language.default in Drupal 8

HelpTopicSection::create in core/modules/help_topics/src/Plugin/HelpSection/HelpTopicSection.php

Creates an instance of the plugin.

InstallerTestBase::setUp in core/modules/simpletest/src/InstallerTestBase.php

Sets up a Drupal site for running functional and integration tests.

InstallerTestBase::setUp in core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php

install_begin_request in core/includes/install.core.inc

Begins an installation request, modifying the installation state as needed.

SelectProfileFormTest::setUp in core/tests/Drupal/FunctionalJavascriptTests/Core/Installer/Form/SelectProfileFormTest.php

UpdatePathTestBase::runDbTasks in core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBase.php

Runs the install database tasks for the driver used by the test runner.

UpdatePathTestBase::runDbTasks in core/modules/system/src/Tests/Update/UpdatePathTestBase.php

Runs the install database tasks for the driver used by the test runner.