MAGETWO-32185: WAI-ARIA in Layered Navigation and Customer Dropdown

- fixed preference pageLayoutGeneratorPool for backend

Author: Natalia Momotenko

app/code/Magento/Backend/etc/adminhtml/di.xml

@@ -17,7 +17,13 @@
     <preference for="Magento\Backend\App\ConfigInterface" type="Magento\Backend\App\Config" />
     <preference for="Magento\Framework\App\Response\Http\FileFactory" type="Magento\Backend\App\Response\Http\FileFactory" />
     <preference for="Magento\Framework\View\Layout\GeneratorPool" type="Magento\Backend\Model\View\Layout\GeneratorPool" />
-    <preference for="pageLayoutGeneratorPool" type="Magento\Backend\Model\View\Layout\GeneratorPool" />
+    <type name="Magento\Framework\View\Result\Page">
+        <arguments>
+            <argument name="layoutReaderPool" xsi:type="object">pageConfigRenderPool</argument>
+            <argument name="generatorPool" xsi:type="object">Magento\Backend\Model\View\Layout\GeneratorPool</argument>
+            <argument name="template" xsi:type="string">Magento_Theme::root.phtml</argument>
+        </arguments>
+    </type>
     <preference for="Magento\Framework\View\Layout\Reader\Block" type="Magento\Backend\Model\View\Layout\Reader\Block" />
     <preference for="Magento\Framework\Model\ActionValidator\RemoveAction" type="Magento\Framework\Model\ActionValidator\RemoveAction\Allowed" />
     <preference for="Magento\Framework\Session\Config\ConfigInterface" type="Magento\Backend\Model\Session\AdminConfig" />