Some main plugin types got a shorter path to find plugins.
Before
core/modules/ckeditor/src/Plugin/ckeditor/plugin/Internal.php
After:
core/modules/ckeditor/src/Plugin/CKEditorPlugin/Internal.php
Previously what was $owner/$type, from the proposals above, will be $owner$type (represented as a single directory, no slash), for example:
-namespace Drupal\ckeditor\Plugin\ckeditor\plugin;
+namespace Drupal\ckeditor\Plugin\CKEditorPlugin;
-namespace Drupal\block\Plugin\system\plugin_ui;
+namespace Drupal\block\Plugin\PluginUI;
-namespace Drupal\block_test\Plugin\block\block;
+namespace Drupal\block_test\Plugin\Block;
-namespace Drupal\language\Plugin\Core\Condition;
+namespace Drupal\language\Plugin\Condition;
Views is the exception
Views plugins still maintain a complex directory structure, for example:
core/modules/views/src/Plugin/views/field/Boolean.php
The pattern
{module_name}/src/Plugin/views/{[display, field, filter, cache, ...]}/{PluginName}.php
This change notice simply describes namespace path changes that have occurred during the Drupal 8 development cycle. See the Annotations-based plugins documentation page to learn out how to create a new plugin in your module.
Individual Plugin Change Notices
Archiver
ImageToolkit
CKEditorPlugin
Condition
Block
FieldFormatter
FieldType
FieldWidget
Mail
DataType
Action
Filter
ImageEffect
