MAGETWO-82999: magento#11697 Theme: Added html node to page xml root, cause validation error magento#11858

Author: Oleksii Korshenko

lib/internal/Magento/Framework/View/Layout/etc/layout_merged.xsd

@@ -9,6 +9,7 @@
     <xs:include schemaLocation="urn:magento:framework:View/Layout/etc/elements.xsd"/>
     <xs:include schemaLocation="urn:magento:framework:View/Layout/etc/head.xsd"/>
     <xs:include schemaLocation="urn:magento:framework:View/Layout/etc/body.xsd"/>
+    <xs:include schemaLocation="urn:magento:framework:View/Layout/etc/html.xsd"/>
 
     <xs:element name="layout">
         <xs:annotation>
@@ -45,6 +46,7 @@
             <xs:element ref="referenceBlock" minOccurs="0" maxOccurs="unbounded"/>
             <xs:element name="body" type="bodyType" minOccurs="0" maxOccurs="unbounded"/>
             <xs:element name="head" type="headType" minOccurs="0" maxOccurs="unbounded"/>
+            <xs:element name="html" type="htmlType" minOccurs="0" maxOccurs="unbounded"/>
         </xs:choice>
     </xs:complexType>