After [28883], ensure that priorities have callbacks before returning `true` in `has_filter()`.

Adds unit tests.

Props boonebgorges.
Fixes #29070.

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`WP_List_Table::items` should be `public`, not `protected`. It is accessed in a subclass directly via `wp_ajax_get_comments()`.

See [28493].
Fixes #29072.

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After [29201], use `aria-label` instead of `aria-labelledby` in `WP_Plugin_Install_List_Table::display_rows()`.

Props nvwd, DrewAPicture.
Fixes #28853.

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Media Grid: reduce the padding for `.attachments`.

Props ocean90, ryelle.
Fixes #29085.

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In `media.view.AttachmentFilters.All`, make `uploaded` conditional upon `media.view.settings.post.id` and include a new filter: `unattached`.

Drop the `mime-types` filter and related class (which was added for Media Grid) and use `all` instead. 

Props ocean90, wonderboymusic.
Fixes #29065.

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Media Grid: remove some unused Trash/Delete handler logic. Rendered useless since [29266] and made official by [29322].

See #28819.

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Media Grid: add screen reader labels with more context to filters and bulk actions. Ditto for list view.

Props afercia.
Fixes #29026.

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MediaElement upgrade: cleanup for generated markup for videos. 

See #29110.

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Video: use `auto` instead of actual height for the responsive wrapper in generated markup.

See #29110.

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wptexturize: After [28727], leverage RegeEx possessives (++) to improve performance and avoid libpcre segfaults.

Props kovshenin.
Fixes #12690.

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git-svn-id: http://core.svn.wordpress.org/trunk@29209 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Revert [29428] to avoid errors with Add Media for now.

See #29026.

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Add screen reader text to list table date dropdown.

See #29026.

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Create a new Backbone view, `media.view.Label`, which can be used as a subview in things like toolbars, which need screen reader text.

Make an initial instance of it for the label for Bulk Actions in Media Grid.

See #29026.

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Media Grid: add screen reader text in a subview on the toolbar, a `media.view.Label` instance before `media.view.DateFilter`.

See #29026.

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git-svn-id: http://core.svn.wordpress.org/trunk@29213 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Revert styling changes to the Attachment Details modal from [29289]. fixes #28844.

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Media Grid: use a `media.view.Label` instance in the toolbar for the screen reader text for Search.

See #29026.

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Media Grid: 

* Use a `media.view.Label` instance in the toolbar for the screen reader text for the "all" dropdown.
* Adjust the spinner's priority.

Fixes #29026.

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JSHint after [29437].


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git-svn-id: http://core.svn.wordpress.org/trunk@29217 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Mark `WP_List_Table::bulk_actions()`'s argument `$which` as optional for BC.

Fixes #29026.

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After [29360], add rules for `<input>`s in the scope of `.media-sidebar`.

Props ocean90.
Fixes #28647.

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