9 files declare their use of ViewTestBase in Drupal 8

BlockContentTestBase.php in core/modules/block_content/src/Tests/Views/BlockContentTestBase.php

CommentTestBase.php in core/modules/comment/src/Tests/Views/CommentTestBase.php

FieldTestBase.php in core/modules/field/src/Tests/Views/FieldTestBase.php

HandlerTestBase.php in core/modules/views/src/Tests/Handler/HandlerTestBase.php

NodeTestBase.php in core/modules/node/src/Tests/Views/NodeTestBase.php

PluginTestBase.php in core/modules/views/src/Tests/Plugin/PluginTestBase.php

TrackerTestBase.php in core/modules/tracker/src/Tests/Views/TrackerTestBase.php

UITestBase.php in core/modules/views_ui/src/Tests/UITestBase.php

WizardTestBase.php in core/modules/views/src/Tests/Wizard/WizardTestBase.php